Part A:
We have the following expression:
5x2b2 + 14xb2 - 3b2
Rewriting we have:
b2 (5x2 + 14x - 3)
b2 (5x-1) (x + 3)
Part B:
We have the following expression:
x2 - 18x + 81
Rewriting we have:
(x-9) (x-9)
(x-9) ^ 2
Part C:
We have the following expression:
x2 - 121
Rewriting we have:
(x-11) (x + 11)