1) (3х²-2х)+( -х²+3х)=3х²-2х-х²+3х=2х²+х=х(2х+1)
2)(4с²-2cd)(-10c²+8cd)=4c²-2cd+10c²-8cd=14c²-10cd=2c(7c-5d
3)(12m²-7n-3mn)-(6mn-10n+14m²)= 12m²-7n-3mn-6mn+10n-14m²= 3n-2m²-9mn
4) (3n³-3mn+4m³)-(2mn+3n³)=3n³-3mn+4m³-2mn-3n³=4m³-5mn
(-14×3-21×2-28×3)×2abc...(разложили выражение на множители)
(-42-42-84)×2abc
-168×2abc
-336abc
X3y = x2y2
3y = y2x
2y = 2x
x=y