# Posts by MAry

Total # Posts: 3,863

math
simplify the expression 14/(3x)+(x+5)/(3x)

Pre-Calculus
Simplify arctan 1/3 + arctan 2/3(round to the nearest degree).

Trig
Thank you <3 you are a lifesaver!

Trig
Whoops I forgot to include the diagram...here it is: i.imgur [dot] com/RRY5pox.png

Trig
This has to do with vectors...I'm wondering if I set up the diagram correctly? A plane has a speed of 250mph and flies with a bearing of N35degE. The wind is blowing from the west at 25 mph with a heading of due east. What is the actual speed and heading of the plane?

Trig
This has to do with dot products (I can't make the arrow above the u, i, or j). Given u = 4i - 6j and v = -3i + 5j, find 4u-(1/2)v Am I just supposed to plug in what u and v are equal to in 4u-(1/2)v? If so, is the answer (35/2i - 53/2j)

presential esential
Explain why academic and professional research must use credible sources.

presentation essential

presentation essential
dentify and evaluate the three specific credible sources of information on that topic based on the information on evaluating sources in your textbook on pages 179 – 181. Identify and discuss the criteria that were used to evaluate those three sources and provide evidence ...

Algebra
I have four problems I'm having trouble with. I need to solve the equations by completing the square. 1) w^2 - 5w = 11/4 2) z^2 + 11z = -21/4 3) k^2 - 8k - 7 = 0 4) v^2 - 7v + 1 = 0

math
Usually you will be given the area of the irregular base. If so, it would be the area of the base x height.

maths
The basic formula for a rate/distance/time formula is rate x time = distance bomber: 500 k/hr x (t+2.5)hours = distance (t=time, and the bomber flew 2.5 hours longer than the fighter) fighter: 750 k/hr x t hours = distance Since the two distances are the same, the two ...

Trig
Using law of sines, this is what I got: x/sin37° = 100/sin10° x = 346.6 ft h/sin47° = 346.6/sin90° h = 253.5 ft Is this wrong...?

Trig
From a certain distance from the base of a Giant Sequoia tree a surveyor determines that the angle of elevation to the top of the tree is 47deg. The surveyor then walks 100 feet away from the tree and determines that the angle of elevation to the top of the tree is now 37deg. ...

Calculus 1A
The problem is: Verify the given linear approximation at a=0. Then determine the values of x for which the linear approximation in accurate to within 0.1. LN(1+x) ≈ x I found f(0) = 0 and f'(0) = 1 I have an equation: LN (1+x) -(.1) < x < LN(1+x) + 1 The answer...

Math
A rhombus is a square that has been somewhat flattened (look it up on the Internet). It has 4 equal sides, just like a square. If all of the sides added together equal 64, and if all four sides are equal to each other, what is 64 divided by four sides?

U.S/history AP

parametric equations
On what intervals of t is the curve described by the given parametric equation concave up? Concave down? x=t^2; y=t^(3)+3t

Quantum Physics
Problem 5 plz

Calculus 1A
I am so confused! The problem is: Verify the given linear approximation at a=0. Then determine the values of x for which the linear approximation in accurate to within 0.1. LN(1+x) ≈ x I found f(0) = 0 and f'(0) = 1 I have an equation: LN (1+x) -(.1) < x < LN(1...

Finding the distance
Find the distance d(P1,P2) between the points P1 and P2 P1=(-1,5);P2=(2,4) d(P1,P2)=

victoria has 2 pounds of flour she uses 2/5 of the flour on pizza and then uses 3/10 of the flour for bread. Find the weight of the package of flour that she has left, express in decimal answer.

Math
I am not sure. That's what the questions says

Math
You bought an oil company stock for \$83K per share. The price of the stock lost \$16M during a six month period. Find the price of the stock at the end of the six months. How do I do this?

Trig
Solve the equation on 0° ≤ θ < 360° and express in degrees to two decimal places. sin(2θ) = -0.7843 I've gotten 308.345° (QIV) and 231.655° (QIII). I'm unsure how to get the answer though? The final answer is: 115.83°, 295.83°...

Chem
how do you find the molarity of NaOH if 23.64ml of its solution is needed to neutralize .5632g of KHC8H4O4?

Science
The following heats of formation are used to find the change in enthalpy for the formation of tin chloride in the following reaction Sn (s) + 2Cl2(g) --> SnCl4(l).Sn(s) + Cl2(g) --> Sn Cl2(l) DH = -186.2 kJSnCl2(s) + Cl2(g) --> SnCl4(l) DH = -325.1 kJWhat is the ...

math - college algebra
If the rational function y = r(x) has the vertical asymptote x = 9, then as x →9+, either y → ____or _____

Quantum Physics
5A i 0 0 -i 5b -i 0 0 i 5C -1 -1 -1 3a is 2nd option 3b is 2nd option 6C,6D,8C,8D please

Quantum Physics

Algebra
What is the correct factorization of x^2(x-8)+5(8-x)?

Algebra
Explain how to factor the difference of two squares.

chemistry
How much water must be added to 440. mL of 0.204 M HCl to produce a 0.139 M solution? (Assume that the volumes are additive.)

Algebra
A rock is dropped from a riverbank that is 4 feet above the surface of the river. After how many seconds does the rock hit the surface of the water? At highest?

math
Actually, the problem states that Jo has to read 1/2 of a 100 page book. It also asks what percent of the assignment is left. So: 38/50 x 100 = 76% read. 100 - 76 = 24% left to read.

Physics
What is the wavelength of a 512 Hz sound wave in 20 degree C air?

Maths
Suppose Z=a+bi , where a and b are integers and i is the imaginary unit. We are given that |1+iZ| = |1-iZ| and |Z-(13+15i)|<17 . Find the largest possible value of a+b

Maths
The vertices of a cube are labeled with the numbers 0,1,2,3,4,5,6 and 7, such that no two vertices are labeled with the same number. The sum of any 2 numbers on an edge is prime. What is the maximum sum of the 4 numbers on a face?

Maths
How many ordered sets of positive integer triples (a,b,c) are there such that a+b*c=100

Algebra
When factoring an equation, how do I know if the result is prime? For example, I have a problem x^2 - 2x + 4 and I think it is prime because I can't solve it. Am I right?

Algebra
I have several of these problems and am having trouble getting the hang of it. Can you help me? Factor. If the result is the square of a binomial, write it as such. If the result is prime, so state. Here are the first couple of problems. 1) x^2 + 7x + 12 2) x^2 - x - 12 3) x^2...

math
The total fencing around a square field is 80 yards. The field has an area of how many square yards?

Chemistry
I am trying to do the next one but I am still confused. Would the next one simply be HA+OH^- ----> H2O + A^- ?

Chemistry
You are given an assignment to make 250ml buffer solution having 0.25M weak acid and 0.2M of its conjugate base. You have stock solutions 1.5M acid and 0.5M of the conjugate base. Clearly explain how you are going to make this buffer solution. Can anyone please help me!!!

Solve for x? 0 = -9/5 x -9

math
Write an inequality that represents the statement: x is less than 4 and greater than 1

algebra
6(15) + 40 = ?

please help with this problem Your dad is taking Biology as part of the veterinarian program at the local community college. This semester he will spend a total of 40 hours in the biology lab, and he will take notes in class 6 hours per week. Define a variable for the number ...

Is it 90+40=130?

solve the equation showing steps please 6(15)+40

please help with this problem Your dad is taking Biology as part of the veterinarian program at the local community college. This semester he will spend a total of 40 hours in the biology lab, and he will take notes in class 6 hours per week. Define a variable for the number ...

Thanks Colin.

x=80

x=60?

solve 10(x+5)=130

Solve the equation 2(x =10)=80

Calculus 1A
thanks!!!!!!

Calculus 1A
I am trying to find: dy/dx for y = sec(tan x) I have the answer, but I have no idea how to get there. I know that the derivative of sec x = sec x tan x and that the derivative of tan x is sec^2 x. But sec doesn't have an x, so ...?

Physics
Which describes the greatest displacement? - walking 3 m east then 3 m north, then 3 m west - walking 3 m north, thrn 3 m west, then 3 m south

Physics
Aoron leaves one cify at noon. He has to be at another city 186 km away at 3:00 p.m, the speed limit the entire wAy is 65 km/h . Can he arrive At the second city on time? Explain

Derivative
I didn't realize I had to omit the y' and I got y(-2x + y)/ (y-x)^3

Derivative
Thank you!!!! i got it :)

Derivative
implicitly differentiate f(x) 2xy= y ^2 find second derivative with relevance to x and y. i get y''= -xy' - y/ (y-x)^2 this is wrong though. can someone please help me. thank you

Algebra I?
((x-3)/(x+1)) > 5 I get x < - 2 everytime I solve it, but apparently this is wrong. Can you please show me the steps? :/

Derivative
with respect to x f(cos x) if f'(x)= 1/x find (f(cos x))' i got tan x sec x this is wrong. please explain. thank you

Chemistry
A scuba diver takes a 2.3 balloon from the surface, where the pressure is 1.1 and the temperature is 28, to a depth of 35 , where the pressure is 4.5 and the temperature is 14.

Chemistry
Thanak you so much for your help, DrBob222

Chemistry
Oh, sorry. I meant to say that solution y has a 10 times higher OH- concentration compared to solution x. I hope it makes sense now. :-) Mary

Chemistry
Solution x has a pH of 4.35. Solution y has 10- times high [OH-] compared to solution x. Solution z has a pH 4.0 units higher than that of solution x. calculate the ration of [H3O+] between solutions x&y and between x&z. What is the pH of solutions y and z? classify each ...

Math
Find the HCF 1) 7x and 9 : nothing 2) x^2(x-4) and x(x-4) : its (x-4)? 3) 6b and 2b^3 : 2b ,? 4) 6(x-1)^2 and 16(x-7)(x-1) : x-1 , 5) 18y,27y, 9xy^2 : 9y 6) 5a^2 and 25a : 5a 7) 6abc, 8ab, 12bc : 2b 8) 9a^2b and 18ab^2 : 9ab

English
The team ______ won the game is my favorite. which word correctly completes the sentence above? a. which b.whom c. who d. that

science
in the digestive tract, mouth is bolus to a. stomach is to chyme b. gallbladder is to insulin c. small intestine is to carbohydrate d. esophagus is to peristalsis

....
hans uses a wheelchair. although he has a ramp to get in his house he finds it difficult to get his wheelchair up the ramp. which modification would make it easier for hans to get in his house? a. increase the length of the ram b. increase friction between the wheels and the ...

....
in the digestive tract, mouth is to bolus as a. stomach is to chyme b. gallbladder is to insulin c. small intestine is t carbohydrates d. esophagus is to peristalsis

English
hans uses a wheelchair. although he has a ramp to get in his house, he finds it difficult to get his wheelchair chair up the ramp. which modification would make it easier for hans to get in his house? a. increase the length of the ramp b. increase the friction between the ...

Math
The radius of a cylindrical construction pipe is 2 feet the pipe is 16 feet long what is the volume use the value 3.144 PI and round your answer to the nearest whole number

HSC/514
I have to choose a healthcare organization and discuss the accountability, internal and external factors I know how to do the assignment. I need to know how to find the names that would have the information available online. what would I google for?

English
The students felt fairly prepared for whatever tests their instructors might give them, after years of studying , however difficult the test might be which group of words is misplaced in the sentence above? a. however difficult they might be b. the students felt fairly ...

science
water freezes in the crack in this boulder and expands. over time, pieces of the boulder will break off. what type of weathering effectis this an example of? a. wedging b. hydration c. carbonation d.reduce pressure

science
two waves are traveling through the a container ofnitrogen . the amplitude of the first wave is .3 cm and the amplitude of the second wave is .9 cm. what is true about the two waves? a. the energy of the first wave is less than the second wave. b. the energy of the first wave ...

Statistics
0.833 inches per gram

early childhood
which of the following is best suited to a formative assessment of progress 1. muscular strength snd endurance 2. body fat analysis 3. flexibility 4. qwareness of self and space

Social Studies
What would be abolished if the limits of the Constitution did not restrict officials?

algebra
correction ..... 1/R=1/R1+1/R2+1/R3

algebra
express R as rational expression 1/R=1/R2+1/R2+1/R3 R FOR R1=5 OHMS R FOR R2=4 OHMS R FOR R3=10 OHMS

..
if you already had the chiken pox you can be arournd a person with the disease without no fear of becoming sick. what feature of the immune system explains this? a. acquired immunity b. cell- mediated immunity c. humoral immunity d. primary immune system

science
which structure is common to both prokaryotic and eukaryotic cells ? a. mitochondria b. cell membrane c. endoplasmic reticulum d. pladtids

math
a satisfaction survey is administered to 568 people. seventy- one people were unsatisfied with the product. which statement is true? a. 1 out of every 8 clients was unsatisfied b. 6 out of 8 clients were satisfied c. 1/4 pf the clients were unsatisfied d. 2/3 of the clients ...

math
which number solves the equation for x 1/3:x=1:3 a. 1/9 b. 1 c. 3 d. 9

math
which would be the approximate metric equivalent to 7 inches? a) 0.63 mm b) 1.4 m c) 12 dm d) 18 cm

math
a new physician saw 841 clients during the first year of her practice and 1,072 the second. which represents the percentage increase in client volume? a. 22% b. 27% c. 78% d. 127%

math
six hundred and thirty miligrams is equal to how many grams? a) 0.063 g b) 0.63 g c)63 g d) 630,000 g

math
a pudding recipe for 50 people calls for 4 cups of sugar. each bag of sugar contains 6 cups. how many bags of sugar will be needed to make this recipe for 300 people? a. 4 bags b. 13 bags c. 24 bags d. 50 bags

English
I need help

English
p w s a f m l x copy the letter string above on a piece of paper. cross out the second and last letters. replace all vowels with the letter C. Insert an O before the second C. cross out the first and third letters. Double the second letter. which letter sequence remains on ...

math
collecting cans and bottles for recycling. the ratio is 8 cans to 9 bottles. If you collected 240 cans how many items did you collect in all. Explain to me how you get the answer, please!

science
the team____ won the game is my favorite a. which b. whom c.who d. that

science
which rna basr sequence wod produce the amino acid sequence : Valine Proline Alinine a.GCGCGUUG B. GUGCCUGCG C. GUUCCCACU D. GCUCUUGCU

science
which rna base sequence would produce the animo acid sequence: Valine ALanine