Question

The length of a rectangle is five feet less than

its width. If the area of the rectangle is 84
square feet, find its dimensions.

Answer 1

Length is w-5

Area = length x width

84 = (w-5)w

84 = w^2 - 5w

0 = w^2 - 5w - 84

0 = ( w - 12 )( w + 7 )

w + 7 = 0 leads to negative measures.

w-12=0 ---> w = 12

width is 12, length is 5 less, or 7