x(x-y)-y(y-x)= x(x-y)+y(x-y)=(x+y)(x-y) m²(x-1)+4(1-x) =m²(x-1)-4(x-1)=(m²-4)(x-1)=(m+2)(m-2)(x-1)a²-4(a-b)² =(a+2a-2b)(a-2a+2b)=(3a-2b)(-a+2b)(2x-3y)²-4x² (3x+y)&su...