The length of a rectangular sheet of metal is 6cm longer than twice its width. If the area of the sheet is 140 cm2. Find it’s dimensions.

Question

The length of a rectangular sheet of metal is 6cm longer than twice its width. If the area of the sheet is 140 cm2. Find it’s dimensions.

Answer 1

L=6+2w

Area = 140 = LW = (6+2w)w + 2w^2 +6w = 140

w^2 +3w -70 = 0

(w+10)(w-7) = 0

w = 7 cm wide

L = 6+2(7) = 20 cm Long

Area = 7(20) = 140 cm^2