[xy(1-x)-2x(y-½)]*2x^3y^2+2x^4y^3（x+1）=(xy-x²y-2xy+x)×2x³y²+2x^5y³+2x^4y³=-2x^4y³-2x^5y³+2x^4y²+2x^5y³+2x^4y³=2x^4y²当x=-1,y=1/2时原式=2...过程正确吗