Question

Y varies inversely with x. If y = 7 when x = -4, find y when x = 2.

Answer 1

Answer:

A. y = -14

Step-by-step explanation:

The phrase “ y varies inversely as x” or “ y is inversely proportional to x” means that as x gets bigger, y gets smaller, or vice versa. This concept is translated in two ways. yx = k for some constant k, called the constant of proportionality, or y = k/x (they are essentially identical though.)

Thus, from given information, we first need to find that constant k to be able to solve for either y or x in the future

y * x = k

7 * (-4) = k

k = -28

Now, we can find what y equals when x = 2:

y * x = k

y * (2) = -28

y = -28/2

y = -14

Answer 2

Answer:

y varies inversely with x:y=k,/x

y=7,x=-4

7=k/(-4)

-28=k

k=-28,x=2

y=-28/2

y=-14