Question

Factor 6a^2 - ab - 15b^2

Answer 1

$6{ a }^{ 2 }-ab-15{ b }^{ 2 }\\ \\ =\left( 3a-5b \right) \left( 2a+3b \right)$

*Used the "trial and error" method and a bit of intuition to come up with an answer.