Question

A rectangle’s width is one-fourth of its length. Its area is 9 square units. The equation l(l) = 9 can be used to find l, the length of the rectangle.

What is the length of the rectangle?

0.75 units
1.5 units
3 units
6 units

Answer 1

6 units

Explanation:

The formula for the area of a rectangle = Length × Width

A rectangle’s width is one-fourth of its length.

W = 1/4 × L

W = L/4

Cross Multiply

L = 4W

A = 9 square units

Hence

9 = L × W

We substitute 4W for L

9 = 4W × W

9 = 4W²

We square root both side

√9 = √4W²

3 = 2W

W = 3/2

W = 1 1/2 unit or 1.5 units

Solving for L = Length

9 = L × W

9 = L × 1.5

L = 9/1.5

L = 6 units

Therefore, the Length of the rectangle = 6 units