Question

A rectangle has an area of 72 square units. The width of the rectangle is 9 units. The length of the rectangle is 2x + 4.

What is the rectangle's length?
A. 6
B. 7
C. 8
D. 9

Answer 1

C length = 8

Explanation:

Area of Rectangle = lw

A = lw Substitute l = (2x + 4) ; w = 9

72 = (2x + 4)9

72 = 18x + 36

36 = -36

36 = 18x

36/18 = x

2 = x

Substitute into l = 2x + 4 ; l = 2(2) + 4; l = 4 + 4 ; l = 8

Answer 2

8

Explanation:

If you plug in the answers it will give you 9x6= 54 which is wrong and 9x7=63 and 9x9=81 but 9x8=72.