homework help

Question

The area of a rectangle is 28 square inches. The lenisgth is 8 more than thrice the width. Find the length and width

Answer 1

Let A = area, L = length, W = width

 

L = 3W + 8

 

A = L * W = (3W + 8) * W = 3*W^2 + 8*W

 

3*W^2 + 8*W = 28

 

3*W^2 + 8*W - 28 = 0

 

(3W + 14) * (W - 2) = 0

 

So W = -14/3 or W = 2.  Width cannot be negative so discard -14/3

 

W = 2, so L = 3W + 8 = 14

 

The length is 14 inches and the width is 2 inches