Answer:
(b + 3)(4b + 5)
Step-by-step explanation:
Given
4b² + 17b + 15
Consider the factors of the product of the b² term and the constant term which sum to give the coefficient of the b- term.
product = 4 × 15 = 60 and sum = 17
The factors are 12 and 5
Use these factors to split the b- term
4b² + 12b + 5b + 15 ( factor the first/second and third/fourth terms )
= 4b(b + 3) + 5(b + 3) ← factor out (b + 3) from each term
= (b + 3)(4b + 5) ← in factored form
