# How do you factor the expression 40p^2-13p-36?

It is $\left(5 p + 4\right) \left(8 p - 9\right)$
You can factor this as follows just remember that $13 = 45 - 32$ hence
40p^2-(45-32)*p-36=40p^2-45*p+32*p-36= 5p*(8p-9)+4*(8p-9)=(5p+4)*(8*p-9)