Answer:
x = 7
Explanation:
The difference between the length and width is 3 , then length = x - 3
area (A) of rectangle = length × width
A = x(x - 3) = 28 , distribute parenthesis
x² - 3x = 28 ( subtract 28 from both sides )
x² - 3x - 28 = 0 ← in standard form
(x - 7)(x + 4) = 0 ← in factored form
Equate each factor to zero and solve for x
x - 7 = 0 ⇒ x = 7
x + 4 = 0 ⇒ x = - 4
However, x > 0 , then x = 7