Answer :
First split the -p into -5p + 4p:
2p^2 +4p -5p - 10
Then you will notice that 2p is in both of the bits on the left, and -5 on both bits on the right:
2p(p+2) -5(p+2)
Then notice the (p+2) is the same for both, so you can put the 2p and the -5 together:
(2p-5)(p+2)
