Question

The cost C(in dollars) of making a square window with a side length of n inches is represented by C = n^2/5+175.A window costs 355$.What is the length in feet of the window?

Answer 1

2 1/2 feet

Explanation:

The cost is said to be ...

355 = n^2/5 +175

180 = n^2/5 . . . . . . subtract 175

900 = n^2 . . . . . . multiply by 5

30 = n . . . . . . . . take the square root

The value of n is the dimension of the window in inches. We want to know the dimension in feet. There are 12 inches in a foot, so the dimension is ...

(30 in)/(12 in/ft) = 30/12 ft = 5/2 ft = 2 1/2 ft

The length of the window is 2 1/2 feet.