1)3x*x-4x+1-x*x+3x-7 2)5y*y*y*y*y*y-3x*x*x+8-6y*y*y*y*y*y+5x*x*x 3)5+10x-6x*x-3x*x+10x-4 4)m+2n*n+n*n*n-n*n*n-3m*m+4m

1)3x*x-4x+1-x*x+3x-7=3х²-4х+1-х²+3х-7=2х²-х-6
2)5y*y*y*y*y*y-3x*x*x+8-6y*y*y*y*y*y+5x*x*x=5·у^6-3х³+8-6у^6+5x³=-y^6+2x³+8
3)5+10x-6x*x-3x*x+10x-4=1+20x-6x²-3x²=-9x²+20x+1
4)m+2n*n+n*n*n-n*n*n-3m*m+4m=5m+2n²+n³-n³-3m²=-m²+2n²+5m