若2x-3y+4=0则x（x*x-1)+x(5-x*x)-6y+7

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