Question

the width of the rectangle is 5 inches less than it's length, and the area is 84 square inches. what are the length and width of the rectangle?

Answer 1

w= l - 5    where w = width and l = length

area = 84 = l*w = l(l-5)

l(l-5) = 84
l^2 - 5l - 84 = 0
(l - 12)(l  + 7) = 0 
l = 12 

length = 12 and width =  7