The answer is 4 + 17p, first distribute 2p(p3+5) which the result is 2p times 6p plus 10p and you end up p4 - 5p + 2p(6p) + 10. Then you combine like terms and you end up p4 -5p + 12p + 10p, and repeat the move (combine like terms) and you end up with p4 + 17p. Then again you combine like terms and you end up 4 + 17p. If your wondering what happened to the p well the p is exactly like multiplying anything by 1.