Odpowiedź:
[tex]Zad\ \ 12\\\\a)\ \ 3(4y-xy-2x+2y^2)+3x(y+2)-2y(3x-3y+1)=\\\\=12y-3xy-6x+6y^2+3xy+6x-6xy+6y^2-2y=10y-6xy+12y^2=\\\\=2y(5-3x+6y)\\\\\\b)\ \ abc(4a+3b-2c)-ab(c^2-2bc-3ac)=\\\\=4a^2bc+3ab^2c-2abc^2-abc^2+2ab^2c+3a^2bc=7a^2bc+5ab^2c-3abc^2=\\\\=abc(7a+5b-3c)[/tex]
