148k views
5 votes
The width of a rectangle is the length minus 4 units. The area of the rectangle is 12 units. What is the width, in units, of the rectangle?​

1 Answer

0 votes

Answer: The Width of the rectangle is 2 units

Step-by-step explanation: The rectangle is given as having length L and width, W.

If the width is equal to the length minus 4 units, then the width can be expressed as L- 4.

If the Area of the rectangle is given as 12 units, then

Area = L × W (Area of a rectangle)

12 = L × (L - 4)

12 = L² - 4L

Subtract 12 from both sides of the equation

0 = L² - 4L - 12

What we now have is a quadratic equation

By factorization, we now have

(L - 6) (L + 2) = 0

Therefore (L -6) = 0 or (L + 2) =0

L = 6, or L = -2

Knowing that the length cannot be a negative figure, L = 6 is the answer

If the width is given as the length minus 4 units, then

Width of the rectangle equals 6 - 4 = 2 units.

User Bram Vanroy
by
4.9k points