For this case we have the following expression:
-5a ^ 2b + 10ab ^ 2 - 20b + 25a ^ 3b
We observe that the term 5b is repeated throughout the expression,
therefore it is a common factor.
So, factoring we have:
5b (-a ^ 2 + 2ab - 4 + 5a ^ 3)
Then, rewriting we have:
5b (a ^ 2 (5a-1) + 2ab-4)
Answer:
The factored expression is given by:
5b (a ^ 2 (5a-1) + 2ab-4)
