The dimensions in inches of a shipping box at you bring it, we ship it can be expressed as width x, length x + 5, and height 3x - 1. the volume is about 7.6 ft3. find the dimensions of the box in inches. round to the nearest inch.

 By definition we have that the volume is given by:
 
 Where,
 w: with
 l: length
 h: height
 Substituting values we have:
 
 Rewriting:
 
 We look for the roots of the polynomial:
 
 We discard the negative roots because we want to find dimensions.
 Thus, the dimensions are:
 
 
 the dimensions in inches are:
 w = 10.2 inches
 l = 70.2 inches
 h = 18.6 inches