分解因式x(x-y)(a-b)-y(y-x)(b-a)化简计算：已知2x-y=0.5,xy=2,求2x^4y^3-x^3

原式=x(x-y)(a-b)-y(x-y)(a-b)
=(x-y)(x-y)(a-b)
=(x-y)^2(a-b)
原式=x^3y^3(2x-y)=(xy)^3(2x-y)=2^3*0.5=8*0.5=4