Answer
$(5a+3b)(a-2b)$
Work Step by Step
When factoring $ax^{2}+bx+c$, we search for factors of $ac$ whose sum is $b,$
and, if we find them, we rewrite $bx$ and proceed to factor in groups.
Here, factors of $(5)\times(-6)=-30$ that add to $-7$ are ....$+3$ and $-10.$
$5a^{2}-7ab-6b^{2}=5a^{2}+3ab-10ab-6b^{2}$
$=\left(5a^{2}+3ab\right)+\left(-10ab-6b^{2}\right)$
$=a(5a+3b)-2b(5a+3b)$
$=(5a+3b)(a-2b)$
