A box shaped like a rectangular prism has a height of 17 in. and a volume of 2720 in^3. The length is 4 inches greater than twice the width. What is the width of the box?

Please solve and explain what I need to do. The choices are:

-10
8
20
40

1 answer

Volume of rect. prism = area of base * height

x = width of base of prism
2x + 4 = length of prism base

2720 = x(2x + 4) * 17