x（x*x-1)+x(5-x*x)-6y+7
=-x+5x-6y+7
=2(2x-3y)+7
=2*(-4)+7
=-8+7
=-1能在写详一点吗-x+5x-6y+7x（x*x-1)+x(5-x*x)-6y+7=x*x*x-x+5x-x*x*x-6y+7=x*x*x-x*x*x-x+5x-6y+7=-x+5x-6y+7=2(2x-3y)+7=2*(-4)+7=-8+7=-1