Add the following polynomials.
1.(6x2 + 5x3 + 2x) + (x2-1)
2. (x3 + 3) + (3x3 + 3x3 - 6x4 - 2x2 - 13 + x)
3.(11y3 - 19) + (4y4+ 1)
4. (- 10y2 +9y4 + 12y3 + 36y - 7) + (9y3 + 8y2-y + 1 + 12ya)
5. (12z5 - 13z6) + (9z4+ 22 - 2 + 1)