Simplify:

(5p-2p^3)+(8p^3-7p

(-8v^4+3v)-(-v^4-5v)

(-7n^2-7)+(5-2n^2)

(5x^4-5x)-(7x-8x^4)

(-5x+6x^2)(-6x^2-5x)

(6-6p)+(2+8p)

4p^3+p-2p^3-4p

3a^4-3+8a^4-4

4x^4-8x-8x+5x^4

6-6n^4+4+5n^4

5+2a+5a-6

-3n^2+4n^4+5n^2+3n^4

6x^4+7-7x^4-8

1+6x^2-5+6x^4

3x-8x^4+3x-5x^4

-8+3n^2+6-2n^2

-7b^3-3b^4-3-2-6b^4-5b^3

-3x+5x^4+5x^2+8x^2+2x-8x^4

-4r^3-2r^4+1+r^3-6+3r^4

4x^3-6x-6-8x^3-5-3x

a+6a^4+7+5a-5a^3-a^4

(-5k^2+8k^4-6k^3)-(8k^2+3k^4+2)

(8+8r+3r^3)-(4r^3-r^4-5)

(3n+2-n^3)+(-4n^3-1+8n)

(-3n+4+7n^2)+(2n^2-5-6n)

(-x^2-x-2)-(2-5x+8x^2)