Question 192702
Note that b is the common factor of the three terms, we must factor it out first.
{{{a^2b + 2ab - 15b}}}
={{{b(a^2+2a-15)}}}
Next factor a^2+2a-15.
{{{a^2b + 2ab - 15b}}}
={{{b(a^2+2a-15)}}}
={{{b(a+5)(a-3)}}}