Find Net Ionic equation for hydrolysis , Expression for equilibrium constant (Ka or Kb) and Value of (Ka or Kb) Net Ionic equations I've got NaC2H3O2 == CH3COO^-+H2O -->CH3COOH+OH^- Na2CO3 ==== CO3 + 2H2O → H2CO3 + 2-OH Kb = [H2CO3] [-OH]2 / [CO3]. Kb =

2. Math help!!!! Thanks in advance!!!!!!!!!!!

Activity |Boys|Girls| Total Walk|3 |6 Bike| 5| 3 Skateboard 2 | 1 Total 1. How many students chose walking as their preferred method of transportation? 6 3 9 none of these 2. How many total students participated in the survey? 10 20 15 none of these 3.

3. Algebra

A model rocket is launched from a roof into a large field. The path of the rocket can be modeled by the equation y = –0.06x² + 9.6x + 5.4 where x is the horizontal distance, in meters, from the starting point on the roof and y is the height, in meters,

4. probability

The lifetime of a type-A bulb is exponentially distributed with parameter λ. The lifetime of a type-B bulb is exponentially distributed with parameter μ, where μ>λ>0. You have a box full of lightbulbs of the same type, and you would like to know

5. Algebra

A catapult launches a boulder with an upward velocity of 184 feet per second. The height of the boulder, (h), in feet after t seconds is given by the function h(t) = –16t² + 184t +20. How long does it take the boulder to reach its maximum height? What

6. Spanish- Sin a or a

I have to chose whether or not the sentence needs preposition a or no a (sin a) 1) ¿Conoces__ alguien que organice fiestas de aniversario? 2)Busco__ alguien que me ayude a organizar la mía. 3)Necesito __ un grupo musical que sea bueno. 4) Lo siento, no

7. Science - Check my answers

1. Which of the following statements best defines tides? when waves get bigger because of an approaching storm the rise and fall of ocean water that occurs about every 12.5 hours **** the rise of ocean water that occurs 12 times a day a giant wave that can

8. Probability

The random variable X is uniformly distributed over the interval [θ,2θ]. The parameter θ is unknown and is modeled as the value of a continuous random variable Θ, uniformly distributed between zero and one. Given an observation x of X, find the

9. chemistry

Based upon the intermolecular forces present, rank the following substances according to the expected boiling point for the substance: MgF2, H2O, HCl, N2

10. Chemistry

(NH4)2S is a strong electrolyte. Determine the concentration of each of the individual ions in a 0.200 M (NH4)2S solution. [NH4] = M [S] = M

11. Calculus1

The strength, S, of a rectangular wooden beam is proportional to its width times the square of its depth. Find the dimensions of the strongest beam that can be cut from a 12 inch diameter cylindrical log.

12. Probability

We have k coins. The probability of Heads is the same for each coin and is the realized value q of a random variable Q that is uniformly distributed on [0,1]. We assume that conditioned on Q=q, all coin tosses are independent. Let Ti be the number of

13. Probability

Let X=U+W with E[U]=m, var(U)=v, E[W]=0, and var(W)=h. Assume that U and W are independent. The LLMS estimator of U based on X is of the form U^=a+bX. Find a and b. Express your answers in terms of m, v, and h using standard notation. a=- unanswered b=-

14. math 7

grade 7 students were surveyed to determine how many hours per day they spent on various activities. The results are shown in the circle graph below. about how many hours per day altogether were spent on watching TV and homework?

15. Probability

Let N be a geometric r.v. with mean 1/p; let A1,A2,… be a sequence of i.i.d. random variables, all independent of N, with mean 1 and variance 1; let B1,B2,… be another sequence of i.i.d. random variable, all independent of N and of A1,A2,…, also with

Two children hang by their hands from the same tree branch. The branch is straight, and grows out from the tree trunk at an angle of 26.1° above the horizontal. One child, with a mass of 43.6 kg, is hanging 1.31 m along the branch from the tree trunk. The

17. chemistry

Sodium metal adopts a body-centered cubic structure with a density of 0.97g/cm3. A. Use this information and Avogadro's number to estimate the atomic radius of sodium. B. If it didn't react so vigorously, sodium could float on water. Use the answer from

18. chemistry

Sodium metal adopts a body-centered cubic structure with a density of 0.97g/cm3. A. Use this information and Avogadro's number to estimate the atomic radius of sodium. B. If it didn't react so vigorously, sodium could float on water. Use the answer from

19. Physics

Alice is going on a picnic and is aware that it will be easier to carry the picnic basket if it balances at the center where the handle is attached. She has placed a 1.55-kg container of potato salad at one end and a 0.675-kg package of hot dogs at the

Some people believe in the force (yes, like in Star Wars). To test if young Anakin Skywalker has the force with him, he is told that some cards that Yoda can see but Anakin cannot contain a picture of a planet, a lightsaber, a laser rifle, or a spaceship.

21. physics

. A sonar signal is sent from a ship and the signal returns from the bottom 3.65 s later. How deep is the ocean if the speed of sound in water is 1,530 m/s?

22. Science

To solve the problem of a polluted stream a scientist traced where the pollution came from. She determined that the pollution was coming from many small sources. She worked on a plan to help reduce the pollution to the stream. This is an example of

23. math

6/16 of children have freckles. of those 1/12 have red hair. how many have red hair and freckles?

24. English II B

Deana created a computer-assisted slide show. To make the slide show legible, what is one thing she needs to avoid? A)typing bullets in a small font B)adding color and effects to the font C)printing handouts on paper D)adding tables and graphics

25. Physics

A turntable rotates counterclockwise at 63 rpm. A speck of dust on the turntable is at θ = 0.57 rad at t = 0 s. What is the angle of the speck at t = 9.5 s? Your answer should be between 0 and 2π rad.

26. Algebra

If an object is dropped from a height of 144 ft, the function h(t) = –16t² + 144 gives the height of the object after t seconds. When will the object hit the ground? • 1.5 s • 3 s • 6 s • 9 s

27. science

To solve the problem of a polluted stream a scientist traced where the pollution came from. She determined that the pollution was coming from many small sources. She worked on a plan to help reduce the pollution to the stream. This is an example of

1.B 2.C 3.A 4.B 5.D 1.“Along the southern coast of Brazil the central plateau descends in high, steep escarpments. It towers over the waves and moves back in ridges, leveling off from the peaks of the coastal ranges … As it continues along to the

29. Physics Help

A graph of wavelength vs. 1/frequency should be a straight line. What are it's slope and y-intercept? I'm not given any graphs or numbers, just this question. And I know that Velocity = frequency x wavelength And that slope is found by rise/run and m=

30. science

What causes mid-ocean ridges to form?

Im not sure these are right.I Tryed my best :D. 1.A 2.B 3.C 4.A or B 5.B 1.“Along the southern coast of Brazil the central plateau descends in high, steep escarpments. It towers over the waves and moves back in ridges, leveling off from the peaks of the

32. physics

A jogger with a mass of 66.0 kg reaches the top of a staircase in 44.0 s. If the distance from the bottom to the top of the staircase is 14.0 m, how much power will the jogger create in climbing the stairs?

33. English II B

A student has completed a freewriting exercise. The result is a paragraph exploring the general theme of war in a literary text. What is the next step in the writing process? 1.gathering details 2.beginning an outline 3.writing an introduction 4.narrowing

34. Math 2

Use the diagram to find the surface area of a triangular prism. Find the area of the two triangular faces. Then find the area of each of the three rectangular faces. What is the surface area? Describe how you solved the problem. Prism has numbers of 4, 3,

35. chemistry

the lattice energy for MgCl2 is -2326 kj/mol, which is much higher than that for NaCl which has a lattice energy of -786 kj/mol. Why is this so? Give at least two contributing factors.

36. Math

A prototype rocket burns 159 gallons of liquid hydrogen fuel each sound during a regular launch. Make a table that shows how many gallons of fuel are burned after 2,3,5, and 10 seconds.

37. physics

A dike in Holland springs a leak through a hole of area 0.60cm 2 cm^2 at a depth of 1.4m m below the water surface. How much force must a boy apply to the hole with his thumb to stop the leak? Express your answer to two significant figures and include the

38. English II B

What is the term for a magazine that is published on the computer? 1. computerized slide show 2. online publication 3. electronic portfolio 4. electronic bulletin board

39. social studies 9

explain why the mohawks and the other first nations would choose to become allies with europeans, even though they knew that all the europeans were a threat to their territory and way of life

40. Grammar

Fill in the blanks with the chosen words. words: after and till because as but for if when since so though unless until while or 1) The children went home. It was getting dark. 2) The boys were allowed to read books. The teacher was absent. 3) Mother told

41. English II B

Need Help Please. A student is thinking about different forums for publishing an editorial. Which of the following would be appropriate? 1.a dramatic reading 2.an anthology 3.a poetry contest 4.a school newspaper

60 kg cheetah reaches a speed of 30 m/s when chasing its prey

43. Maths

Jim has grades of 84, 65, and 76 on three math tests. What grade must he obtain on the next test to have an average of exactly 80 for the four tests?

44. Health

Which would produce a greater number of Calories- a pound of lean meat or a pound of butter? Why is it so?

45. physics

Calculate the water pressure at the base of the Hoover Dam. The depth of water behind the dam is 220m m . Express your answer to two significant figures and include the appropriate units

Multiple-Concept Example 10 provides one model for solving this type of problem. Two wheels have the same mass and radius of 5.0 kg and 0.47 m, respectively. One has (a) the shape of a hoop and the other (b) the shape of a solid disk. The wheels start from

47. Physics

A baby whale gets lost from his mother while swimming through a large underwater canyon. Frantically the baby whale yells for his mommy. 1.5 seconds later, the whale hears his yell's ECHO from the canyon wall. How far is it to the canyon wall? The speed of

62. science

How can water cause both mechanical and chemical weathering?

63. physics

A particular person’s lower leg is 59 cm long and has a mass of 8.0 kg. If allowed to swing freely, with what time period would the leg swing? (Treat the leg as a simple pendulum with length equal to half the leg length and all the leg’s mass

64. Physics

The blades of a motor rotate at a rate of 4401 rpm. When the motor is turned off, the blades slow to a new angular speed of 430 rpm in 4.93 seconds. What is the angular acceleration of the blades (in rads/sec^2)?

65. math

a rectangular painting including the frame is 28 inches wide and 24 inches tall.the opening inside the frame is 24 inches wide and 20 inches tall.what is the area covered by the frame

76. physical science

If You Were Riding A Train List Some Examples Of Items That Would Make It Seem Like You Weren't Moving

77. physics

Does changing the angle of an incline that you are rolling a ball down change any of these paramaters? Final velocity of the ball, work, initial potential energy, and final kinetic energy?

78. science

An ideal gas for which Cv = 3R/2 is the working substance of a Carnot engine. During the isothermal expansion, the volume doubles. The ratio of the final volume to the initial volume in the adiabatic expansion is 5.7. The work output of the engine is 9 x

79. English

What is the purpose of prewriting in the writing process? A) to help polish your writing B) to find details to complete paragraphs C) to organize your thoughts within a draft D) to help develop a topic for writing

80. Spanish

This is online homework that I have done but I am having trouble with 3, 5, 6, 7, and 8. For 3 i put l, for 5 d, for 6 b and for 8 i. But they were in correct. 1) (blank) esta todo bien y esperamos que 2) (blank) tambien lo este. 3) (blank) lo pensemos y

81. physics

In the sketch, the small hydraulic piston has a diameter of 2.5cm cm . The large piston has a diameter of 6.4cm cm . For each newton of force applied to the small piston, how many newtons of force are exerted by the large piston? Express your answer using

82. science

discuss how the structure of a virus correlates with its function

96. Physics!!!

How much work W must be done on a particle with a mass of m to accelerate it from rest to a speed of 0.899c ? Express your answer as a multiple of mc^2 to three significant figures.

97. chemistry

calculate the pH of the solution when 100mL of .05M KF is mixed with 200mL of .05M HF; Ka (HF) = 3.467x10^-4. I tried to use the Henderson Hasselbach equation to get the correct answer (pH=3.16) but can't seem to get it correct. Any help would be AMAZING!

98. statistics

à manufacturer of computers designed to aid social scientists in analyzing research data clams that his computers are opérational for at least 80 percent of the time. during the course of the year one computer was operational for 270 days. test, 1

99. science

PLEASE HELP GUYS An ideal gas for which Cv = 3R/2 is the working substance of a Carnot engine. During the isothermal expansion, the volume doubles. The ratio of the final volume to the initial volume in the adiabatic expansion is 5.7. The work output of

100. social studies

1. which action was NOT an example of telling against society in the 1920s in the united states? a. going to speakeasies b. dancing the Charleston c. women bobbing their hair d. women working outside the home 2. what is the main reason businesses made

101. science

The coils in a toaster convert electrical energy into thermal energy. Heat from the coils is used to toast the bread. How is the heat from the coils transferred to the bread?

how do varieties of informative and positive messages adapt the basic pattern?

103. percentages/word problem

A wholesaler buys plastic lamps for $18 each and sells them for$30.60. What is the percent markup based on cost?

104. Physics

A 4.8 kg container of water sits on a scale A. A cube of aluminum with sides of length 11.0 cm is suspended from a spring scale B so that half of the block is submerged in the water. What is the reading (in N) on spring scale B The continual question is

105. Physics

A spherical hydrogen-filled balloon is used to lift a load of 5950 N (in addition to the weight of the hydrogen). Suppose the density of the air is 1.18 kg/m3. Find the minimum necessary radius for the balloon

106. Geometry

what's the surface area of a right trapezoidal prism

109. Probability

Caleb builds a particle detector and uses it to measure radiation from a remote star. On any given day, the number of particles, Y, that hit the detector is distributed according to a Poisson distribution with parameter x. The parameter x is unknown and is

110. PHYSICS!!!

A boat moves at 7.00m/s relative to the water. (You can neglect relativity at these slow speeds.) The boat travels 100 m downstream and then 100 m upstream, returning to its original point. Find the time for the round trip

111. Math

The great white shark can grow can to a length of 4.9m. The mako shark can grow to a length of 40 dm. Which shark can grow to the greater length?

112. Science

Physical properties used to indicate temperature changes include all of the following except a. color changes of liquid crystals b. volume changes of fluids and solids c. changes in electrical resistance d. odor changes in solids

113. physics.

Rank the following from most to least for the percentage of its volume above the water line: A. Basketball floating in saltwater B. Basketball floating in glycerin C. Basketball floating in gasoline

127. finance

A bond that has a $1000 par value (face value) and a contract or coupon interest rate of 11.1%. The bonds have a current market value of$1125 and will mature in 10 years. The firms marginal tax rate is 34%. The cost of capital from this bond debt is what

128. social studies

What would the highest and lowest points look like on a topographic map?

129. college chemistry

What would the [H3O+] be after addition of 5.15 mL of 0.1000 M HCl to 25.00 mL of 0.1000 B (a weak base, Kb = 6.31e-5)?

130. Social Studies (History)

What did Germany, Italy, Japan, and the Soviet Union aka USSR have in common before WWII? please have four reasons and please explain why these countries had that similarity.

131. Chem

How do you predict when a reaction goes non-spontaneous if you have delta h Stotal and deltaS

132. english-poetry

how can i revise this haiku poem? lunch bell rings change clinking in our pockets striving for food

133. chemistry

what is z effective? Rb+ Al3+ Mg2+ Na+ out of this set which ion is the smallest? which is the largest?

134. physical science

why it is necessary to apply sunscreen to your skin and wear sunglasses when you want sunbathe on the beach?

135. maths

compare and contrast the alpha error and the beta error. how can the two be corrected in the same research?

136. Maths please someone help me out!!!

3. The efficiency of an industrial pump decreases by a fixed percentage each year. The percentage decrease each year is with respect to the efficiency of the pump at the start of each year. Over each four year period, the efficiency decreases by 80%. Let

137. Physic

Why is the potential difference between the terminals of a battery is not always equal to the e m f of a battery

138. Math

John spoke to his friend from 10:15am-11:00am. And then John spoke to that same friend again from 12:30pm-1:15pm. altogether, how many minutes did John speak to his friend? How do I figure this out?

139. science

Finely ground sane can be poured like water. Why is sand considered a solid rather than a liquid? How is sand different than liquids?

140. Math

Solve by factoring: 4x^2+12x+9=0

141. Algebra 2

Please help me solve and find the excluded values for this problem. Also please show me the work for this problem I want to learn!F(h) = x^2-9/x^2-4x+3

142. math-urgent

1. two cards are drawn from a standard of 52 cards. Find the probability that the second card is a spade given that the first card is a club. 2. Suppose you draw 3 cards from a standard deck of 52 cards . Find the probability that the third card is a club

143. chemistry

what is the oxidation half-reaction in the following chemical reaction? fe(s) + 3 agno3 -> ag + fe(no3)3

144. science

1. Why is the periodic table usually drawn with hydrogen (H) separated from the rest of the elements? 2. Finely ground sane can be poured like water. Why is sand considered a solid rather than a liquid? How is sand different than liquids?

145. Calculus

Determine whether the series is convergent or divergent. If it is convergent, find its sum. If it is divergent, enter NONE. sum from 1 to infinity of 1/e^2n. It is convergent, but I do not know how to solve for the sum.

146. Calculus

Determine whether the series is convergent or divergent. If it is convergent, find its sum. If it is divergent, enter NONE. sum from 1 to infinity of (5^n+4^n)/20^n It is convergent, but I do not know how to find the sum.

147. science

The type of heat transfer called convection happens as a result of: a. electromagnetic waves b. the direct contact of particles in a substance c. the actual motion of a fluid in the form of currents d. All of the above I think it's C.

148. physics

Find its density. Express your answer to two significant figures and include the appropriate units How does this compare with the density of water? Express your answer using two significant figures.

149. science

2. Why is it important to protect yourself from certain electromagnetic waves? What are some ways people protect themselves from these waves ?

150. science

How does Newton's first law of motion explain the movement of your body when in a car in which you are riding stops suddenly?

151. science

A researcher determined the amount of electrical energy entering a toaster and the amount of heat given off by the toaster. The amount of heat was less than the amount of electrical energy. How can this observation be explained?

152. science

What happens when light passes from one material to another?

153. science

Suppose you were asked to select one renewable energy resource for use in your town. Which would you select, and why?

154. science

How does Newton's first law of motion explain the movement of your body when in a car in which you are riding stops suddenly?

155. Physics

A particular garden hose has an inside diameter of 15/16 in. The nozzle opening has a diameter of 5/16 in. When the flow speed of the water in the hose is 0.58 m/s, what is the flow speed through the nozzle?

156. CAN ANYONE HELP?

I posted my science (chemistry) question and I have received no help and i really need to get this done so can someone please help??

157. chemistry

How many different N-O bond lengths would you expect to observe in the actual structure of NO3− and why?

158. world history

Distinguishing unique patterns of biodiversity in eastern and western areas of Southeast Asia, the Wallace Line is found between

159. PHYSICS!!

Light travels at about 0.75c in water. A)What's the wavelength in water of light whose wavelength in vacuum is 418nm

160. Algebra

1. Find the quotient: e^2-e-12/e-4 A. e+3/e-4 b. e^2+3 C. e-3 D. e+3 2. Find the quotient: (a^2+11a+30) / (a + 5) A. a+6 B. a^2 + 10a+25 C. a^2 + 11a + 25 D. a+6/a+5 3. Find the LCM for x^2+3x+2 and x^2 +5x+6. A. (x+1)(x+2)(x+3) B. x+1 C. x+3 D. (x+1)(x+3)

161. math

If a 6-sided number cube is rolled twice, what is the probability that a 1 is rolled both times?

162. math

If a sandwich shop sells lunches that include one sandwich and one side dish, draw a tree diagram to represent the number of combinations that are possible if the choices are a ham or turkey sandwich and chips or cookies as the side dish.

163. Maths

4. Calculate average speed of particle which position at time t is given by the function g(t) = t3, on the intervals (a) [2,3]; (b) [2,2.1]; (c) [2,2.0001]; (d) [2, 2 + h] , where h > 0 is arbitrary positive number. Find g′(2).

HELP! How do I solve for x: 4x+2=3x+9

165. Algebra

Simplify (X^3)^-4(-2x^-2)^-3

166. PRE CALC

Evaluate: sigma notation of (3cos k(pi) +1) start value: k=0 end value: k=3

167. physical science

what is the importance of ozone in the stratosphere for your health?what will happen to us when ozone depletion becomes more serious?

168. Algebra

4/b+1 + 1/b2-4 + 5/b+2

169. maths

what is the total of £3.89 x 589

170. Math

How many years would it take a worker making $40 per hour to earn$8,000,000, assuming she works 240 8-hour days per year?

171. Employee Training and Development

The major difference between internet-based training and intra-net based training is:

172. math

what is a leading interval of 5 does it mean 4 or 6

173. Biology

Which is the highest? Ecosystem population community

174. Math - Int Trig

Given the functions: f(x)=2x+2 g(x)=3/x^2+2 h(x)=sqrt(x-2) Find the following 1) (f∘g)(-5) 2) (h∘g)(3) 3) (g∘h)(-2) 4) (g∘g)(-2) 5) (f∘h)(12) Find the following and state the domain: 6) h∘g 7) f∘g 8) g∘f 9) g∘g 10)g∘h

175. Resources for educating young children

A portfolio should?

176. Very tough maths

The number of ways there are to arrange 6 distinct rooks on a 10x10 board such that none of them can attack each other is n. Find the product of the non-zero digits of n.

177. GAMMAR

State the "Tenses" : 1) If it rains like this for a few more hours, the roads will all be waterlogged. 2) He will have finished reading the book by evening. 3) what was he doing when she came?

178. Calculus1

derivative of h(x)= 3(√x) - x(√x)

179. algebra

solve the equation 3/ (x+1) - 1/x =1/2

180. Pre calculus

Find a unit vector in the direction of the given vector. v=(1,-1)

181. Precalculus

Find a unit vector in the direction of the given vector. w=-1-2j

182. Math - Algebra2

Given the functions: f(x)=3x+2 g(x)=3/x^2+2 h(x)=sqrt(x-2) Find the following a) (f∘g)(-5) b) (h∘g)(3) c) (g∘g)(-2) d) (f∘h)(12) Thanks

183. poetry

is this a good poem about the hunger games ? 24 tributes from 12 districts 2 kids from each forced to fight to death Only one comes out alive With 23 others dead 24 tributes in total 12 districts in all As punishment for the rebellion Against district 13

184. Physics

Consider the following distribution of objects: a 4.00-kg object with its center of gravity at (0, 0) m, a 1.20-kg object at (0, 3.00) m, and a 5.40-kg object at (2.00, 0) m. Where should a fourth object of mass 7.00 kg be placed so that the center of

An experiment was conducted to determine the abrasion resistance of a new type of automobile paint. Twelve different strips of metal were painted with the new paint. The abrasion resistance of each piece was then tested on a machine. In the sample, the

186. science

Why is the periodic table usually drawn with hydrogen (H) separated from the rest of the elements?

187. English

In what ways have social media made our lives easier?

188. High school math

What is 2 plus 2

189. Biology

What are the three types of dispersion?

190. algebra

Determine the value of each expression 25% of 200

191. science

Suppose you were designing a statue to be placed outside your school. What materials would you use, and why?

192. Phyiscs

A hollow copper tube (diameter = 4.01 cm) is sealed at one end and loaded with lead shot to give a total mass of 0.218 kg. When the tube is floated in pure water, what is the depth, z, of its bottom end?

193. Geometry

what's the formula for the base area of a right triangular prism

194. Calculus

Given f(x)=−2x^3 -3x + 1, the value of the derivative of the inverse function, f^−1(x) at x=−21 is (f^1)′(−21)= ? please explain how to solve this

ertertertert

196. french

what's wrong with this sentences? 1. Je m'amuse lire quand je m'ennuie. 2. Partie de sa routine quotidienne comprend à se regarder dans le miroir pour se raser avec un rasoir et de la crème à raser. 3. J’ai besoin habituellement de me dépêcher le

197. Math

find the 93rd term for the following pattern. -3, -6, -9, -12,-15 these are equations

198. English

1. Because it was so late, we went home. 2. Because of its lateness, we went home. (Is #2 grammatical?)

199. Math 3

Zach needs to paint all the sides and the tops of these steps, but not the bottom. How many square feet does he need to paint? Explain how you solved dimensions 2,2,4 and 2,2,2. Thanks

200. mathematics

Find x when (x^3 ?2(x^2)?5x+6) is divided by (x-1)

201. math

How many miles does a person travel if she drives a car at 50 miles per hour for 3.5 hours?

202. mathematics

If ?2 is the solution of the equation 2x+1? 3c=2c+3x?7 find the value of c

203. mathematics

Intergrate sin3x dx

204. mathematics

Find the maxizimum value of y in the eaquation y=1?2x?3(x^2)

205. mathematics

3(^2)+6x?2=0 solve the equation

206. maths

If Asquare+Bsquare=16 and 2AB=7. Find the possible values of (A-B)