Question

A rectangle’s base is 6 cm longer than its height. The rectangle’s area is 135 cm2. Find this rectangle’s dimensions. You must include units with your answers

Answer 1

Area of a rectangle  =  length x height

Area = 135

Height = X

Lenght = x +6

135 = x * x+6

Simplify:

135 = x^2 +6x

Subtract 135 from both sides:

x^2 + 6x - 135 = 0

Solve:

2 numbers when added need to equal 6 and when multiplied equal -135

x = 9 and x = -15

The height can't be a negative number so the height is 9

Length =  9 +6 = 15

Height = 9cm, Length = 15 cm