Suppose your sat score is 2040 a college with an average sat score for admitted students of which of these would most likely be your best opinion
a. 1640
b. 2060
c. 1220
d. 1480

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