Question

Factor -5a^2b + 10ab^2 - 20b + 25a^3b

Answer 1

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)

Answer 2

Factor out the GCF, which is 5b, and you get: 5b(5a^3-a^2+2ab-4)