Odpowiedź:
[tex]a)\ \ (a^3+b-2c)(x^2-y)=a^3x^2-a^3y+bx^2-by-2cx^2+2cy\\\\\\b)\ \ (x-y)(a-2b-1)=ax-2bx-x-ay+2by+y\\\\\\c)\ \ (a-c)(2a+c-3)+ac=2a^2+ac-3a-2ac-c^2+3c+ac=\\\\=2a^2-3a-c^2+3c\\\\\\d)\ \ -5x^2+3x(x-1)+(2x-1)(x+3)=-5x^2+3x^2-3x+2x^2+6x-x-3=\\\\=2x-3\\\\\\e)\ \ 3y^2-2x(x+2y)-(x-y)(2x+y)=3y^2-2x^2-4xy-(2x^2+xy-2xy-y^2)=\\\\=3y^2-2x^2-4xy-2x^2-xy+2xy+y^2=4y^2-4x^2-3xy[/tex]
