Question

Suppose x varies directly with y and x=24 when y =-96. what is the constant of variation and what is the value of x when y=-164?

A. cov = -4, x=656
B. cov = -4, x=41
C. cov = -1/4, x=41
D. cov= -1/4, x=-41

Answer 1

Choice B is correct.

Explanation:

Firstly, we have to find constant of variation.

y= kx eq(1)

Given y= -96 and x= 24

put above values in eq(1)

-96=k(24)

dividing above equation by 24

-96/24=24k/24

-4=k

so eq(1) becomes y=-4x

Secondly, we have to find value of x when y=-164

-164=-4x

dividing by -4 by above equation.

-164/(-4)=-4x/(-4)

41=x

so, k=-4 and x=41.

Answer 2

B

Explanation:

30. You want to solve for k and use it with a different y-value.

... y = kx

... -96 = k·24

... -96/24 = k = -4

For y = -164, you have

... -164 = -4·x

... -164/-4 = x = 41

The coefficient of variation is -4, x is 41.