1) 2(x-y)+y(x-y) = (х - у)(2 + у);
2) 2x-2y+cx-cy = (2x-2y) + (cx-cy) = 2•(x-y) + с•(x-y) = (х-у)(2+с).
1) 2(x-y)+y(x-y) = (х - у)(2 + у);
2) 2x-2y+cx-cy = (2x-2y) + (cx-cy) = 2•(x-y) + с•(x-y) = (х-у)(2+с).