Б)5х(х-у)-2(у-х)^2=5x^2-5xy-2(y^2-2xy+x^2)=5x^2-5xy-2y^2+4xy-2x^2 =3x^2-xy-2y^2
г)(x-5)(6+4x)-3(1-x)^2=6x+4x^2-30-20x-3(1-2x+x^2)=6x+4x^2-30-20x-3
6x-3x^2=x^2-8x-33
Б)5х(х-у)-2(у-х)^2=5x^2-5xy-2(y^2-2xy+x^2)=5x^2-5xy-2y^2+4xy-2x^2 =3x^2-xy-2y^2
г)(x-5)(6+4x)-3(1-x)^2=6x+4x^2-30-20x-3(1-2x+x^2)=6x+4x^2-30-20x-3
6x-3x^2=x^2-8x-33