Q:

the volume of olivia’s rectangular lunchbox is 240 cubic inches. the lunchbox is 3 inches deep, and its length is 2 inches more than its width. what is the width of olivia’s lunchbox?

Accepted Solution

A:
The volume of the rectangular prism is:
 v = (w) * (l) * (h)
 Where,
 w: width
 l: length
 h: height
 Substituting values we have:
 240 = (w) * (w + 2) * (3)
 Rewriting we have:
 80 = (w) * (w + 2)
 80 = w ^ 2 + 2w
 w ^ 2 + 2w - 80 = 0
 The roots of the polynomial are:
 w1 = -10
 w2 = 8
 We use the positive root because we are talking about dimensions.
 w = 8 inches
 Answer:
 The width of olivia's lunchbox is:
 w = 8 inches