# Math

posted by Stephen

a/b + b/a = x
a/b - b/a = y

in the equation above, if a is (not equal) to 0 and b is (not equal) to 0, which of the following must be equal to x^2-y^2?
a. 2
b. 4
c. ab/2
d. a^2 b^2/2
e. 4a^2b^2

1. Reiny

x^2 - y^2 = (x+y)(x-y)

but x+y = a/b + b/a + a/b - b/a = 2a/b
and x-y = a/b + b/a - a/b + b/a = 2b/a

so (x+y)(x-y) = (2a/b)(2b/a) = 4

## Similar Questions

1. ### random variables

For the standard normal random variable Z, compute the following probabilities. For the following problems, use four decimal places. 16. P (0 less than or equal to Z less than or equal .9) 17. P (-1.3 less than or equal to Z less than …
2. ### Math

a/b + b/a = x a/b - b/a = y in the equation above, if a is (not equal) to 0 and b is (not equal) to 0, which of the following must be equal to x^2-y^2?

Using the simplex method, solve the following linear programming problem: Maximize: P= 5x+2y Subject to: 4x+3y < or equal to 30 2x-3y < or equal to 6 x > or equal to 0, y > or equal to 0.
4. ### Physics

True or false?equal masses of two different gases placed in containers of equal volume at equal temperature must exert equal pressures
5. ### math

State the null hypothesis, Ho, and the alternative hypothesis, Ha, that would be used to test the following statements. (a) The linear correlation coefficient is positive. Ho: ñ ---Select--- not equal to equal to greater than less …
6. ### Math

1) When will the dependent variable in the equation y=√x+4-3 equal or exceed to 4?
7. ### Geometry

The lengths of the sides of a triangle are 17, 8, and n. Which of the following must be true?
8. ### Kaycee

A charge q equals to 3.4c is located at x equal 2m and y equal 2m and a second charge q2 equal to 2.7c is located at x equal 4m and y equal -4m..where must a third charge q be placed such that the resolutant force on it is zero .
9. ### math

7. The tennis team is selling key chains as a fundraiser. If its goal is to raise is at least 180, how many key chains must it sell at \$2.25 each to meet that goal?
10. ### Math

What is the solution to the nearest tenth to the equation below?

More Similar Questions