Разложите на множители: 2) х²+у²+2ху-(х+у)³ ; 4) (m+2n)³-m²+4n² ; 6) (х+3у)²-х³-9х²у-27ху²-27у³

2) х²+у²+2ху-(х+у)³ =(x+y)²-(х+у)³=(x+y)²(1-x-y)
4) (m+2n)³-m²+4n² =(m+2n)³+(2n-m)(2n+m)=(m+2n)(m²-4mn+4n²+2n-m)
6) (х+3у)²-х³-9х²у-27ху²-27у³=(х+3у)²-(3*y+x)³=(x+3y)² * (1-3y-x)