(3х+х²)-3у-ху=х(3+х)-у(3+х)=(3+х)(х-у)
а³-8=(а-2)(а²+2а+4)
1) 3x- 3y+x^2y- xy^2 = 3(x-y) + xy(x- y) = (x-y) (3+xy)
2) a^3- 8 = (a- 2) (a^2+ 2a+4)
