The length of a rectangular air filter is 5 inches less than twice the width. Find the length and width of the filter if the area is 375 square inches.

Question

length and width

Answer 1

A = lw

l = 2w - 5

 

375 = (2w - 5)w

2w² - 5w - 375 = 0

(2w + 25)(w - 15) = 0

 

2w + 25 = 0 

2w = -25

w = -12.5

 

This answer is out because measurements are not negative.

 

w - 15 = 0

w = 15

 

l = 2(15) - 5

l = 25