Answer:
(x + 3)(x + 5)
Explanation:
Assuming you require the expression factored.
Given
x² + 8x + 15
Consider the factors of the constant term (+ 15) which sum to give the coefficient of the x- term (+ 8)
The factors are + 3 and + 5, since
3 × 5 = 15 and 3 + 5 = 8 , thus
x² + 8x + 15 = (x + 3)(x + 5) ← in factored form