If x varies inversely with y and x = 4 when y = 8, find x when y = 16.

Solution:

The statement is x ∝ 1/y

Where inverse variation is 1/variable

Introduce k, which is the constant of variation to convert it into an equation

y = k × 1/x

y = k/x

In order to determine k, use  x = 4 when y = 8

8 = k/4

k = 8×4 = 32

The equation here is x = 32/y

From the question as y = 16

x = 32/16 = 2

Therefore, x = 2 when y = 16.

If x varies inversely with y and x = 4 when y = 8, find x when y = 16.

Summary:

If x varies inversely with y and x = 4 when y = 8, x = 2 when y = 16.