I'm good at things but when it comes to math I'm bad, pls end my suffering. ;-;

Find the sum of the following. Show your solution. pls.

1.) 3x2-2+x and 7+x2-3x
2.) 2x2+3x3-1and 4x2+2x
3.) 6x-3x2y+y and 4y-2x+2x2y
4.) 12x2+9x-8 and 8x2-4x+6
5.)2x+2y-3z and x-5y+8z