(p^2-3p^4- 2) + (8p^2+ 4 + 9p^4) - (6p^2-7p + 5)=

(p^2-3p^4- 2) + (8p^2+ 4 + 9p^4) - (6p^2-7p + 5)

p^2-3p^4- 2 + 8p^2+ 4 + 9p^4 - 6p^2 + 7p - 5

p^2 + 8p^2- 6p^2 -3p^4+ 9p^4 + 7p - 5- 2+ 4

3p^2 + 6p^4 + 7p - 3