г) ax+ay-x-y = a(x+y) - (x+y) = (x+y)(a-1)
д) 1-bx-x+b = -bx + b - x + 1 = b(-x+1) - (x-1) = b(1-x) - (x-1) = b(1-x) + (1-x) = (1-x)(b+1)
е) xy + 2y-2x-4 = y(x+2) - 2(x+2) = (x+2)(y-2)
Ответ: г) (x+y)(a-1); д) (1-x)(b+1); е) (x+2)(y-2)