Answer:

Sana makatulong po, ayan lang po yung lumabas.

Answer:

7b(b+1)(b-3)

Step-by-step explanation:

7b³ – 14b² – 21b

factor the expression

7b (b²+b-3b-3)

factor the expressions

7b (b (b+1)-3 (b+1))

factor the expression

7b(b+1)(b-3)

final answer: 7b(b+1)(b-3)