Question

If y varies inversely as x, and y = 4 as x = 8, find y for the x-value of 2.

16 10 8 14

Answer 1

y = k/x

We want to find k first.

4 = k/8

4(8) = (k/8)(8)

32 = k

We now need to find y knowing that k = 32 and x = 2.

y = k/x

y = 32/2

y = 16

Did you follow?

Answer 2

16

Explanation:

Inverse variation follows this equation:

y = k/x

We know one point, so we input x and y, and solve for k.

4 = k/8

k = 32

The inverse variation equation is

y = 32/x

Now we let x = 2, and use our equation to find y.

y = 32/2

y = 16