Question 751646
We need a pair of numbers that add to -26 and multiply to 120. After searching we find -20 and -6.


{{{
8a^2-20a-6a+15
}}}

rearranging and placing parentheses...

{{{
(8a^2-20a)-(6a-15)
}}}

removing gcds and factoring...


{{{
4a(2a-5)-3(2a-5)=(4a-3)(2a-5)
}}}



:)