Answer:
(x + 1)(x + 3)
Step-by-step explanation:
Given
x² + 4x + 3
Consider the factors of the constant term (+ 3) which sum to give the coefficient of the x- term (+ 4)
The factors are + 1 and + 3, since
1 × 3 = 3 and 1 + 3 = 4, then
x² + 4x + 3 = (x + 1)(x + 3)