2. If y varies inversely as x and

y = 3 when x = 5, find x when y = 2.5

Step-by-step explanation:

From the law of variation,

y 1/x, where is the constant of proportionality. Therefore

y = k/x where k is a constant

3 = k/5 and k = 15

To find x when y = 2.5 (5/2)

Go back to the second equation

y = k/x

5/2 = 15/x

When you cross multiply

5x = 30.

Divide through by 5,

x = 6.