Answer:
x + 7 and x + 5 are possible dimensions
Explanation:
x² + 12x + 35 ← factor the quadratic
consider the product of the factors of the constant term (+ 35) which sum to give the coefficient of the x- term (+ 12)
the factors are + 7 and + 5 , since
7 × 5 = + 35 and 7 + 5 = + 12 , then
x² + 12x + 35 = (x + 7)(x + 5) ← in factored form
now the area A = length × breadth , that is
A = x² + 12x + 35 = (x + 7)(x + 5) , then
length = x + 7 or x + 5
breadth = x + 5 or x + 7