Question

y varies directly as the square root of x, and y = 12, when x = 49. Find the value of y when x = 225.​

Answer 1

180/7

Explanation:

Direct variation:

y varies directly as k

y = kx

y varies directly as √x

y = k√x

We need to find k. We use the given data to find k.

y = 12 when x = 49

12 = k√49

12 = 7k

k = 12/7

The equation of direct variation is

y = (12/7)√x

x = 225

y = (12/7)√225

y = (12/7)(15)

y = 180/7