Answer:
b² + 10b + 21
Step-by-step explanation:
First: b²
Outer: 7b
Inner: 3b
Last: 21
b² + 7b + 3b + 21 =
b² + 10b + 21
Answer:
[tex](b + 3)(b + 7) \\ b(b + 7) + 3(b + 7) \\ b {}^{2} + 7b + 3(b + 7) \\ b {}^{2} + 7b + 3b + 21 \\ b {}^{2} + 10b + 21[/tex]
hope this will help u :)