A box shaped like a rectangular prism has a height of 17 in and a volume of 2,720 in³ The length is 4 inches greater than twice the width. What is the width of the box?

• –10 in
• 8 in
• 20 in
• 40 in

2 answers

17*w*(2w+4) = 2720
2w^2 + 4w = 160
w^2 + 2w + 1 = 80+1 , I completed the square
(w+1)^2 = 81
w+1 = ± √81
w = -1 ± 9
= 8 or some negatiave, which I will reject

the width = 8 inches
Thank you