Question

The width of a rectangle is the length -3 units. The area of the rectangle is 40 units. What is the width, in units, of the rectangle

Answer 1

Width of the rectangle is 5 units

Explanation:

• Step 1: Let the length of the rectangle be x. Then the width = x - 3. Find dimensions if area = 40 sq. units

Area of the rectangle = length × width

⇒ 40 = x (x - 3)

⇒ 40 = x² - 3x

⇒ x² - 3x - 40 = 0

⇒ x² + 5x - 8x - 40 = 0 (Using Product Sum rule to factorize)

⇒ x(x + 5) - 8(x + 5) = 0

⇒ (x + 5)(x - 8) = 0

⇒ x = -5, 8 (negative value is neglected)

x = 8 and x - 3 = 5