Question 392587
a^(2)b+2ab-15b

Factor out the GCF of b from each term in the polynomial.
b(a^(2))+b(2a)+b(-15)

Factor out the GCF of b from a^(2)b+2ab-15b.
b(a^(2)+2a-15)

In this problem 5*-3=-15 and 5-3=2, so insert 5 as the right hand term of one factor and -3 as the right-hand term of the other factor.
b(a+5)(a-3)