suma y resta de polinomios

1.-(7x²+2)-(3x²-5)=
4x²+7

2.-(8x²-x)-(7x²+3x)=
1x²-4x

3.- (3 x²-2x-1)-(4x²+2x+5)=
1x²-4x-6

4.-(-3x+x²-1)-(5x+1-3)=
4x²-8x

5.-(-1x²+7-2x)-(5x+3x²-7)
4x²-7x+6

6.-(7x³-x²+x-1)-(2x²+3x+6)=
7x³-3x²-2x-7

7.-(5x²-2x+5)-(3x³-x²+5)=
3x³+6-x²2x

8.-(3x²-x-7)-(5x³+5x²-+2x)=
5x³+4x²-3x-12

9.-(6x³-2x²-3x+1)-(-x³-x²-5x+7)=
7x³-1x²+2x-6

10.-(x-3x²+x³+9)-(-8+7x-x²+x³)=
-2x²-6x+17