Question

The area of a rectangle is 72cm2 the Length of the rectangle is 6cm longer than the width

Answer 1

A) W * L = 72
B) L = W + 6
A) W = 72 / L Substituting this into B
B) L = 72 / L + 6 Multiplying both sides by "L"
B) L^2 = 72 + 6L
B) L^2 -6L -72 = 0
L = 12
Width = 6
 

Answer 2

Let the width be x
then length = x + 6

area = x(x+6)
72 = x^2 + 6x
x^2 + 6x - 72=0
x^2 + 12x-6x -72 = 0
x(x + 12 ) - 6 ( x + 12) = 0
(x-6) (x+12) = 0

width = 6
length = 6+6 = 12