Question

The width of a rectangle is the length minus 3 units. The area of the rectangle is 54

units. What is the width, in units, of the rectangle?

Answer 1

Width of the rectangle is 9 units

Explanation:

• Step 1: Let the width of the rectangle be x. Then the length = x - 3. Find dimensions if area = 54 sq. units

Area of the rectangle = length × width

⇒ 54 = x (x - 3)

⇒ 54 = x² - 3x

⇒ x² - 3x - 54 = 0

⇒ x² + 6x - 9x - 54 = 0 (Using Product Sum rule to factorize)

⇒ x(x + 6) - 9(x + 6) = 0

⇒ (x + 6)(x - 9) = 0

⇒ x = -6, 9 (negative value is neglected)

x = 9 units