Answer:
(x + 5)(x + 4)
Step-by-step explanation:
Given
x² + 9x + 20
Consider the factors of the constant term (+ 20) which sum to give the coefficient of the x- term (+ 9)
The factors are + 5 and + 4, since
5 × 4 = 20 and 5 + 4 = 9, thus
x² + 9x + 20 = (x + 5)(x + 4)
