# Questions Asked onMarch 27, 2014

11. ## physics

Some say that the hot air balloons with which the Montgolfier brothers performed their first flight had a volume of 1700 cubic metres and could lift 780 kilograms (that includes the balloon, basket and payload). Assume that the balloon took off on a day

39. ## Physics.

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

40. ## Chemistry

I would really like to understand how to do these problems, because my exam is coming up in a few weeks. I still cannot comprehend how you can tell if a system is is positive or negative according to reaction. For #1, I presume it is E if it is spontaneous

41. ## WORD PROBLEMS UGH

Chef kim plans to serve a fruit plate to each of 336 diners at a banquet. Each plate will contain 6 slices of kiwi fruit, 3 pieces of mango, and 5 strawberries. If a mango yields 5 pieces and a kiwi fruit yields 8 slices, how many fruits are needed?

42. ## Dimensionless parameters

The drag, D, on a sphere located in a pipe flow through which a fluid is flowing to be determined experimentally. Assume that drag is a function of the sphere diameter, d, the pipe dianeter, H, the fluid velocity, V, and the fluid density, p. a) What

43. ## Global Studies

Although the Amazon Basin receives more than 80 inches of rain per year, South America also has the driest place on Earth, know as a. Death valley b. Gobi desert c. Atacama desert*** d. the Caribbean

44. ## physics

Two electrons start at rest with a seperation of 5e-12 metres. Once released, the electrons accerelate away from each other. Calculate the speed of each electron when they are a very large distance apart.

45. ## math

Two tracking stations 50 miles apart sight a weather ballon. The angle of the ballon from one of the stations is 45° and from the other is 60°. What is height of the balloon?

46. ## statistics

An airline company is considering a new policy of booking as many as 161 persons on an airplane that can seat only 140. (Past studies have revealed that only 81% of the booked passengers actually arrive for the flight.) Estimate the probability that if the

47. ## math

vehicles lose value over time. A car is purchased for $23 500, but it is worth only$8750 after eight years. What is the average annual rate of change in the value of the car, as a percent?

48. ## science- Physics

Two electrons start at rest with a seperation of 5e-12 metres. Once released, the electrons accerelate away from each other. Calculate the speed of each electron when they are a very large distance apart.

49. ## World History

What role did the Jacobins play in the French Revolution? The Jacobins reached an agreement with moderate French leaders to end the revolution. The Jacobins opened French gov't to full participation by women. The Jacobins returned France to a monarchy by

50. ## Social Studies

The excerpt below is Article 6 of the "Declaration of the Rights of Man," the document that founded the French Republic on August 26, 1789. Use this excerpt below to answer the following question: Law is the expression of the general will. Every citizen

51. ## Math

What is 7 sqrt 8 - 2 sqrt 8?

52. ## Math

I was wondering if you can help me with math real quickly. I just cant figure this out. For the first question I have to find the surface area for the given cylinder. I have to use 3.14 and round to the nearest whole number. The radius is 6ft and the

53. ## 8th Grade U.S History

Document F Andrew Jackson, Proclamation to the people of South Carolina, December 10, 1832 I consider that the power of one state to annul a law of the United States is not consistent with the survival of the Union. Nullification is forbidden by the

54. ## Math

in triangle PQR, PQ=5.4, QR=3.6, and PR=6.2. to the nearest tenth, what is m

55. ## physics

The drawing shows a collision between two pucks on an air-hockey table. Puck A has a mass of 0.0430 kg and is moving along the x axis with a velocity of +5.41 m/s. It makes a collision with puck B, which has a mass of 0.0860 kg and is initially at rest.

56. ## geometry

In triangle GHJ, GH=32, HJ=63, and m

57. ## university of calabar

A stoppered flask at 25 0C contains 250 ml water, 200 ml octanol, and 50 ml of air. An unknown amount of o-xylene is added to the flask and allowed to partition among the phases. After equilibrium has been established, 5.0 mg of o-xylene are measured in

58. ## physics

A typical volume of a modern hot air balloon is 2500 cubic metres, and a typical maximum temperature of the hot air is 120 degrees Celsius. Given these figures, and an outside air temperature and density of 15 $$^{\circ}C$$ and 1.225 $$kg/m^3$$

59. ## Math

Write a rule in function notation to describe transformation that is a reflection across the x-axis. A. Ry-x(X,Y) B. Rx-0(X,Y) C. Rx-y(X,Y) D. Ry-0(X,Y)

60. ## physic

A stationary 2.0 kg object is located on a table near the surface of the earth. The coefficient static friction between the surface is .80 and the coefficient of the kinetic friction is 0.65. A horizontal force of 5N is applied to the object. Determine the

61. ## Science URGENT

Write down the number of hydrogen and oxygen atoms of the following H2O 3H2O 5H2O Write down the number of carbon, hydrogen and oxygen atoms: C6H12O6 2C6H12O6 10C6H12O6 Write down the number of molybdenum, oxygen and hydrogen atoms: Mo(OH)4 3Mo(OH)4

62. ## Chemistry

Silver ion reacts with excess CN− to form a colorless complex ion, Ag(CN)−2, which has a formation constant Kf=3.0×1020. Calculate the concentration of Ag+ in a solution prepared by mixing equal volumes of 2.3×10−3M AgNO3 and 0.21M NaCN.

63. ## Calculus

If e^x = 243 and e^y = 32 then e^((3x + 4y)/5) =? The answer is 432, but I don't understand why.

64. ## physics

For the purposes of this problem, there are three parts to the figure, and the center of mass of each one is shown in the drawing. These parts are: (1) the torso, neck, and head (total mass = 40.4 kg) with a center of mass located on the y axis at a point

65. ## senior problem solving

a colony of ants doubles every 20 days. if the colony has 350 ants today, how many are/were present in 50 days? a. in 50 days? b. 55 days ago? c. in 30 days?

66. ## Math

The weather forecaster says it's 20 degrees Celsius in London but only 28 degrees colder in New York. What is the temperature in New York?

67. ## MATH WORD PROBLEM

Diego works at a toy store. His boss tells him to order 420 stuffed bears and toy cars. He must order 4 stuffed bears for every 3 toy cars. a) If he must order 9 large stuffed bears for every 7 small stuffed bears, how many of each stuffed bear should he

68. ## Chemistry

I am having a hard time figuring out how to write a balanced equation for the reaction of iron and oxygen to produce iron(II) oxide. I also need a balanced equation for the reaction of iron and oxygen to produce iron (III) oxide. I would appreciate any and

69. ## math

vehicles lose value over time. A car is purchased for $23 500, but it is worth only$8750 after eight years. What is the average annual rate of change in the value of the car, as a percent?

70. ## math

Air is pumped into a balloon such that its volume increases at the rate of 75cm^3 per second. It is assumed that the balloon is spherical all the time. Find in term of pi the rate at which the radius of the balloon is increasing when the radius is 5cm.

71. ## Chemistry

copper(1) chloride reacts with hydrogen sulfide. if 9.90 grams of copper(1) chloride and 10.2 grams of hydrogen sulfide are reacted together, what is the limiting reactant?

72. ## physic

A stationary 2.0 kg object is located on a table near the surface of the earth. The coefficient static friction between the surface is .80 and the coefficient of the kinetic friction is 0.65. A horizontal force of 5N is applied to the object. Determine the

73. ## Maths

A box contains pns and pencils in the ratio 6 : 5. There are 24 pens. How many pencils are there?

74. ## chemistry

calculate the grams of solute neede to prepare 24 grams of a 13.5% by mass scurose (c12h22o11) solution

75. ## Statistics

The following are the weekly amounts of welfare payments made by the federal government to a sample of six families: $143,$138, $132,$136, $145 and$136. What is the range? $24$9 $13$0

suppose she cut the cake into 8 equal size pieces and 6 people at all the pieces. Explain how they could have divided the pieces so that everyone ate the same amount of cake. You can show your work in a drawing.

77. ## government

How do ideological parties and single-issue parties differ from one another? A. Ideological parties tend to be more liberal, while single-issue parties tend to be more conservative. B. Ideological parties focus on certain beliefs, while single-issue

78. ## Physics

two groups of paddlers meet in the middle of a lake. after a brief visit a person in canoe 1 pushes on canoe 2 with a force of 46 N . Mass of canoe 1 is 150 kg and mass of canoe 2 is 250 kg. find acceleration of each canoe

79. ## Physics

Calculate the average force per nail when Sarah (following figure), who weighs 130 pounds, lies on a bed of nails and is supported by 600 nails. Express your answer using two significant figures.

80. ## FINANCE

Polycorp has a current dividend of $5.00 due tomorrow and is expected to pay a dividend$5.50 at the end of the first year. Its dividend is expected to grow at 8% pa for the following year. Dividends are then expected to grow at 4% pa for another two

81. ## personal finance

The interest rate is composed of _____ and the ______? a. risk-free rate,risk discount b.risk free rate, risk premium c.risk free rate, default risk premium d. none of the above

82. ## statistics

A committee consists of five men and four women. Two people are selected at random from the committee. What is the probability that one man and one woman will be selected?

83. ## Statistics

For the most recent seven years, the U.S. Department of Education reported the following number of bachelor's degrees awarded in computer science: 4,253; 5,578; 6,406; 7,334; 8,728; 11,298; 15,182. What is the annual arithmetic mean number of degrees

84. ## Math

How many possible combinations are there if a spinner with 4 sections is spun twice?

85. ## Chemistry

How would you exactly start the first problem? My thermodynamic skills is a bit rusty. I am assuming I have to use ΔH°f under the given reaction..? But then..we barely covered ΔG° in class. Am I to use this equation, ΔG° = ΔH° - T ΔS°? Umm..can

86. ## Chemistry

a balloon has a volume of 2.0 L at room temperature (27 degrees celsius). at what temperature would the balloon have a volume of 2.0L?

87. ## trig

A plane is flying due south at a speed of 192 mph. a wind is blowing in at 53 degrees at 13 mph. what is the bearing of the plane?

88. ## Physics.

The top floor of a building is 40m above the basement. Calculate how much greater the water pressure is in the basement than on the top floor. Express your answer to two significant figures and include the appropriate units.

89. ## Electricity

A 10 nF capacitor is charged to 5 V. How much charge does it store?

90. ## Chemistry

a.) How much energy is emitted in each alpha decay of plutonium-234 if 234Pu, 234.0433mu and 230U, 230.0338mu. b.) The half-life of plutonium-234 is 8.8 hrs. How much heat is released by the alpha decay of a 1 micro-gram sample of plutonium-234 in a

91. ## Calculus

An object in free fall has its distance from the ground measured by the function d(t)=-4.9t^2 +50, where d is in meters and t is in seconds. If gravity is the only acceleration affecting the object, what is gravity's constant value?

92. ## math

There are 10 different pairs of shoes in a wardrobe. Find the probability of the event that there is at least one pair among them in choosing 4 shoes by chance. Express your answer in rational form.

93. ## Calculus

Posted by MG on Wednesday, March 26, 2014 at 6:54pm. The hands of a clock in some tower are 4.5m and 2m in length. How fast is the distance between the tips of the hands changing at 9:00? (Hint: Use the law of cosines) The distance between the tips of the

94. ## Chemistry URGENT

Could someone let me know if I have balanced these equations correctly. balanced equation of the reaction of iron and oxygen to produce iron(ii)oxide. 2Fe + O2 = 2FeO Also if the balanced equation of the reaction of iron and oxygen to produce

Keith played some games of chess at a tournament. He recorded the results of the games on the table shown. Game Results: Number of Games TIES 4 WINS 12 Losses 4 If Keith plays 10 more games, how many of the 10 games is he likely to win? A. 6 games B. 8

96. ## Physics

Pressure = weight density × depth Calculate the water pressure at the bottom of the 50-m-high water tower shown in the photo. Express your answer to two significant figures and include the appropriate units

97. ## finance

Polycorp has a current dividend of $5.00 due tomorrow and is expected to pay a dividend$5.50 at the end of the first year. Its dividend is expected to grow at 8% pa for the following year. Dividends are then expected to grow at 4% pa for another two

98. ## geometry

Mr. Franco is making a triangular cement slab and needs to set boards before he can pour the cement. He has already set two boards that are 5 feet and 8 feet in length. What is a reasonable range for the length of the third board that Mr. Franco could set

99. ## physics

A 6.26-g bullet is moving horizontally with a velocity of +344 m/s, where the sign + indicates that it is moving to the right (see part a of the drawing). The bullet is approaching two blocks resting on a horizontal frictionless surface. Air resistance is

100. ## science

the distance a car travels between the time the driver decides to stop the car and the time the driver puts on his brake is called the reaction distance how does the reaction distance change with speed

101. ## analytical chemistry

What volume (in liters) of 0.96 M KOH solution should be added to a 0.130 L solution containing 10.2 g of glutamic acid hydrochloride (Glu, FW=183.59; pKa1=2.23, pKa2 =4.42, pKa3=9.95) to get to pH 9.90?

102. ## physics

which of the following would be the best example of non damped simple harmonic motion? A. mass oscillating vertically on a spring B. sound waves propagating through water C. light waves propagating through a vacuum D. guitar strings vibrating

103. ## psych

Men growing beards because women consider men with beards as good mates is an example of A. intersexual competition. B. intrasexual competition. C. macrosexual competition. D. microsexual competition.

104. ## science

3 moles of pesticide of molecular mass 200 g/mole is applied to a closed system consisting of 20 m3 of water, 10 m3 of air, 1 m3 of sediment, and 0.001 m3 of fish. Determine the concentration and amount in both grams and mole units in air, water, sediment

105. ## Geometry

I need help in this problem: A 14-foot ladder is leaning against a house so that its top touches the top of the wall. the bottom of the ladder is 8 feet away from the wall. which of these can be used to find the height of the wall? A. in a right triangle

106. ## Calculus

A weight oscillates in a vertical motion according to the position function y(t)=-5 cos(t). Assuming t≥0, when will the acceleration if the weight be zero for the first time?

107. ## sew

Mrs. Shotto was once one of your regular customers, but she hasn't asked to have any garments made in approximately one year. You note she has lost weight. She would like you to make her a special silk blouse to replace a favorite blouse that has worn out.

The weights (in grams) of the contents of several small bottles are 8, 4, 3, 6, 7, 1 and 5. What is the sample variance? 5.81 4.33 5.67 2.22

109. ## CALCULUS problem

There are four parts to this one question, and would really appreciate if you could show and explain how you get to the answer, because I tried looking up how to find the answer myself, but nothing made sense. Thank you! 11. The region R is bounded by the

117. ## chemistry

Upon decomposition, one sample of magnesium fluoride produced 1.65 kg{\rm kg} of magnesium and 2.58 kg{\rm kg} of fluorine. A second sample produced 1.50 kg{\rm kg} of magnesium. How much fluorine (in grams) did the second sample produce?

118. ## geometry

| (3,2)\ | / \ | /(s,1) \|/ -----------------|------------------- /|\ / | \ | | In the accompanying figure, the slope of line k is t and the slpe of line m is negative t. What is the value of s? (the lines are perpendicular) (sorry for the ascii graph ^_^)

119. ## eviromental science

Using two or three well-developed paragraphs, explain how temperature and precipitation determine which plants grow within an area and give an example.

120. ## Mathematics

Give the first three terms of the sequence of 1.Tn+1=Tn+n

129. ## who dare to give the answer!

i have passed class -9 with 10 CGPA.in DAV public school,and it is affiliated to CBSE.but,now i want to change my school.and take admission in class -10 in a different school,and it is also affiliated to CBSE board,under the same zone.is it possible for

asked by hurry its a question of my career.
130. ## Algebra 2

Simplify the rational expression (x^2+xy-2y^2)/(x^2+3xy+2y^2)

131. ## Social Studies

Hai I was wondering if you could check my answer? It doesn't really talk about this in my text book, and it doesn't really help if I look it up online. Q: Founded by the Mormons, which city was originally called Deseret? A. San Diego B. Provo C. Santa Fe

132. ## physics

calculate the magnitude of the electrical force between object a with a chaarge of 15mc and object b with a charge of 3mcc. they are located 0.4m apart.

133. ## Physics

Object A has a mass of 443 kg. Object B has a mass of 356 kg. If they are separated by 3.4 m, what is the magnitude of the gravitational force between them?

134. ## Math

If x+15 and 2x+27 represent the number of degrees in measures of two consecutive angles of a parallelogram, find the value of x.

135. ## History

What federal document did Susan B Anthony quote in the beginning of her speech in I believe 1872? I know she was trying to equal rights between women, and I think it would make sense for it to be the preamble to the Federal Constitution. Opinions?

136. ## math

can you produce a 2-digit whole number by multiplying two-digit whole numbers?

137. ## english

A French girl found them

138. ## Geometry

Given the lengths of the sides of a triangle, identify the triangle as acute, right, or obtuse. 37,12,34 5,12,13 20,21,28

139. ## physics

A weight oscillates in a vertical motion according to the position function y(t)=-5cos t. Assuming t>=0 (greater than or equal to), when will the acceleration of the weight be zero for the first time?

140. ## algebra 1

your local rollerblade rink will rent you blades for $14.00 for 3 hours or$29.00 for 8 hours. Asume the price increase is constant depending on the number of hours the blades are rented.

141. ## math

450 divide 14?

142. ## Math

Fay is making 13 bows to sell. She has 36 feet of ribbon. If each bow requires 2 1/4 feet of ribbon, how much ribbon will not b used

143. ## geometry

The perimeters of 2 similar polygons are 12 and 16. 1. What is the ratio of the lengths of 2 corresponding sides? 2. What is the ratio of the areas? 3. If the area of the smaller polygon is 54 what is the area of the larger polygon?

144. ## Heat Transfer

A 1 m square verticalplate is heated to 300 deg C and placed in room air at 25 Deg C. calculate the heat loss from the one side of the plate

145. ## math help!!

factor: (x^2+5x)^2 - 36 and (a-b)^2 - (c-d)^2 show the steps pleasee!

146. ## math

a right triangle has a hypotenuse that is 59 miles long. One side is 1.05 longer than the other. What are the lengths of the two legs

147. ## Persuasive Writing help

I'm writing a persuasive request but English is not my native language. I've done many drafting and revising, but still not sure. so I would be grateful if you could show me what I did wrong and the correct way to revise it. Thanks "Dear xxx, I would like

148. ## Math

You have cards numbered 1-10 and a number cube what are the odds of getting two prime numbers? The book says 1\5 but how do they get it.

149. ## Math

There are 120 students trying out for the play. Only 5% of those trying out will have a speaking part. Write this percent as a fraction in its lowest terms.

150. ## Math

Rewrite the equation y - 37x = 82 as a function of x. I got f(x)= -37x +82 is that right?

151. ## MATH HELP

.................| .........(3,2)\..|../ ...............\.|./(s,1) ................\|/ -----------------|------------------- ................/|\ .............../.|.\ .................| .................| In the accompanying figure, the slope of line k is t

152. ## Introduction to Criminal Courts

Analyze and explain the importance of a college degree for someone seeking to join the police or police training. Analyze and explain how higher education plays a pivotal role in advancement and promotions in the police department. Analyze whether higher

153. ## programming

a program displays the name of fruits that are sorted from the arrays(program that sort five names)

154. ## Math

Try to make 24 using -,+,•,/ 1,5,4,3 & 3,12,4,1 & 10,9,7,2

155. ## English

I can stand that much to help the environment. --------------------------- What is the part of speech of 'that much' in the sentence? English - Writeacher, Tuesday, March 25, 2014 at 7:53am The sentence doesn't make sense. What does "can stand" mean here?

156. ## FINANCE

A ninety day bank bill with 90 days to maturity has a price of \$99427.95. What is the effective annual yield implied by this price and maturity? Be careful I am not asking for the annual nominal yield, which by convention is normally quoted in financial

157. ## FINANCE

Many creditors of your firm offer early payment discounts. The accounts payable supervisor does not believe in paying early “as the bank overdraft rate of j12 = 8% pa is more than the average 2% offered for payment within 10 days from date of invoice”.

This is my last question. What is the domain of the function below? f(x)= e^(x-4)-2 I got all real numbers is that correct?

159. ## English

After watching a documentary about the environment on TV, I decided to start my own project,"Project Green Kid." Today was my first day as a Green Kid...... ---------------------------------- Do we have to use "a Green Kid"? What about "a green kid"? Why

6 (31n+5)

161. ## Chemistry

How many grams of C would be necessary to produce 790. grams of CaCO3 by the sequence of reactions shown below? Step 1: CaO + 3C → CaC2 + CO Step 2: CaC2 + N2 → CaCN2 + C Step 3: CaCN2 + 3H2O → CaCO3 + 2NH3

162. ## social study

what are the ways of solving enviromental problems in your communities?

163. ## Geometry

If I have 64 ft what are all the dimension of the rectangular patios I can make using all 6 ft?

164. ## Chemistry

The main radioisotope in a banana is potassium-40, a beta emitter with an activity of 242 Bq/g. An average medium banana has about 320 mg of potassium and the natural abundance of potassium-40 is .0117%. Calculate the value of the BED in a.) Gy b.) Sv

165. ## chemistry

write a reaction that show solid copper (II) nitrate dissociating.

166. ## math

I have a flat piece of plywood that measures 45 inches in width and 75 inches in length. I want to cut the board into identical square pieces with the integer side lengths and use the entire piece of wood. What are the dimensions (width & length) of each

asked by He who should not be named
167. ## Calculus

If y=cos x, what is y^(6) (x)?

168. ## math help

factor: (a-b)^2 - (c-d)^2

169. ## health

The one area you can't control to reduce your chances of stroke, heart disease, or diabetes is

170. ## Math

Can 26x^2 be written as x*sqrt26?

171. ## Math

What is the domain of the function f(x)= -3^(x+3)+4? I got (-infinity, infinity) is that correct?

172. ## Composition

How does taking observations obstruct or halt the writing process

What is the median of 29, 49, 27, 64, 79, 59, 29 and 41? 29.0 45.0 59.5 49.0

174. ## English

1. In the evening, Sonya's father cooks dinner. 2. In the evenings, Sonya's father cooks dinner. 3. Evenings, Sonya's father cooks dinner. 4. Every evening, Sonya's father cooks dinner. (What is the difference of the four sentences in meaning?)

176. ## English

Do I use an apostrophe after the A or not? "He got 5 As on the final exam." I've heard that capital letters are made plural only by adding an s, but my textbook gives this example-How many A's did you write on the paper?

177. ## English

Did I classify this sentence correctly? The (A) birds (SN)/ in (P) the (A) tree (OP) sang (V) happily (adv) during (P) the (A) day (OP).

178. ## Equation help

X^2-6x+7=0 1.-1.59,4.41 2.-1.59,-4.41 3.1.59,-4.41 4.1.59,4.41 Can someone help?

179. ## English

1. In the evening, Sonya will meet one of her friends. 2. In the evenings, Sonya will meet one of her friends. ------------------------- Thank you for your help. What is the difference between them. Does #1 mean "She will meet her friend this evening

180. ## Count Of Monte Cristo

How does the Count of Monte Cristo set up Mondego & Villefort? How does he frame Villefort and what happens to Villefort?

181. ## Math

In triangle ABC, m

182. ## math help ASAP!!

factor: 2m^3 - 7m^2n - 15mn^2

183. ## health

Cosmetic surgery is more likely to lead to disappointment if a person is ________. A. Seeking surgery with the hope of influencing a change in oneself B. Seeking surgery with the hope of influencing a change in someone else C. Seeking surgery with the hope

184. ## math help!!

Factor: 2(2x^2-x)^2-3(2x^2-x)-9

185. ## Math

Reggie is a long distance runner. His daily 2-1/2 hour practice is divided evenly into three areas: warm-ups, running, and cool down. How many minutes total does Reggie spend warming up and cooling down each day at practice?

186. ## Math

What is the domain of the function f(x)=2^(x+3)-1? I got (-infinity, infinity) is that correct?

187. ## Math

What is the domain of the function f(x)= x+6? I got -infinity < x < infinity

188. ## math

There are 2 leaves along 3 in.of an ivy vine. There are 14 leaves along 15 in. of the same vine. How many leaves are there along 6 in. of the vine?

189. ## Math 117

Why is it important to find nonperfect roots in radical form to simplify the process of performing basic operations with radical expression?

190. ## maths

at present, a firm is manufacturing2000 items.it is estimated that the rate of change of productionp w.r.t. additional number of workers x is given by dp/dx =100-12x.if the firm employs 25 more workers ,then the new level of production of items is

191. ## math

What is the rule if 8 is the input and 23 is the output

192. ## math

how do you factor: (a - b)^2 - c^2

Samara keeps her collection of hair bows in a box. She has 20 white bows, 20 red bows, 15 yellow bows, 25 green bows, and 20 pink bows. If she pulls out 1 bow at random, what is the probability the bow will be yellow? Can someone show me how to work this

194. ## math

What percent of 25 is 23?

195. ## math

What percent of 600 is 84?

196. ## math

factor: -20x^2 + 5y^2