x varies inversely as y², and x = 4 when y = 10. find x when y = 2.
x = 16 , x = 5, x = 80, x = 100

Solution:

x varies inversely as y²,

This inverse proportion can be written as x ∝ 1/y² 

x = n/y² where n is the constant of proportionality.

x = 4 when y = 10

Substituting it in the formula

4 = n/10²

n = 100 × 4 = 400

When y = 2 we have to find x

x = 400/2²

x = 400/4 = 100

Therefore, x = 100 when y = 2.

x varies inversely as y², and x = 4 when y = 10. find x when y = 2.
x = 16 , x = 5, x = 80, x = 100

Summary:

x varies inversely as y², and x = 4 when y = 10. x = 100 when y = 2.