化简:—(—3x-y+2x)-{-x+[4x-(x-y-z)-3x]+2z}(用由里向外去括号与由外向里去括号2

化简：{2/3x-2/(x+y)[(x+y)/3x-x-y]}/(x+y)/x 化简3x-2/(x+y)[(x+y)/3x-x-y]÷(x-y)/x 化简 3x(x^2-x-1)-(x+1)(3x^-x) X^3(x-y)+x(y-x) 化简:(x-3y)(x+y)-(x-2y)(x+2y)-(x-y)平方 化简:5(x-y)+2(x+y)-3(x-y) 化简3(x-y)-7(x--y)+2(y-x) —2x+5(x+2y)—(x—3y) 3x+2(y-x)-(-x-4y) (x-2y)-(y-3—2x+5(x+2y)—(x—3y) 3x+2(y-x)-(-x-4y)(x-2y)-(y-3x) 化简y(x+y)+(x+y)(x-y)-x^2 化简：{2/3x-2/(x+y)[(x+y)/3x-x-y]}/【(x-y)/x】的负二次方 化简(X-2Y)-(Y-3X) 化简：3x（2x+y)-2x(x-y) x是字母x不是乘号 若x+y分之x-y=3,求式子x+y分之5(x-y)—2(x-y)分之x+y的值 若x-y分之x+y=3,求式子x+y分之5(x-y)—2（x-y）分之x+y的值 x(x-y)2-(y-x)3 [2/3x-2/x+y(x+y/3x-x-y)]/x-y/x 计算2/3x-2/x+y(x+y/3x-x-y)/x-y/x (x+y)-(x-y)^3÷(x-y)(x+y)×2y化简e , 化简：2x-{-3y+[4x-(3x-y]}