Question

If y varies inversely with x and y =5 when x=20 find x when y = -4​

Answer 1

x=-25

Explanation:

Inverse variation

xy =k

We know x and y

20*5 =k

100 =k

So the formula is

x y = 100

We know y = -4

x (-4) = 100

Divide each side by -4

-4x/-4 = 100/-4

x = -25