Width of the rectangle is 9 units
Step-by-step explanation:
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