of the following polynomials 1) (12x³ - 2x²-x+3) and (x²+x-4)
2) (4x² + 5x-4) and 2(x²-3x + 2)
3) (3x²+x²-1) and 3(-x³+²+5)
4) 2(x² + 3x + 4) and (-2x²-5x + 1)
5) (8x²-3x²+x-1) + 3(x²+2x-5)​