11x+9y-x+y怎么化简?

11x+9y-x+y怎么化简? (x-y)(x+y)-(x-2y)(2x+y)请问怎么化简. (-2x+6y)的平方-(3x+2y)(2x-3y)+(-9y)*4怎么化简 (x-y) 除以√x-√y 怎么化简 (x-y)²-4(x+y)²怎么化简? (10x+y)-(10y+x)怎么化简 [2000+20(x-y)]/x+y = (2000-20y)/y 怎么化简 因式分解(x+y-z)*[(x+y)^2+(x+y)*z+z^2]怎么化简 怎么化简-2(x-3y) 3(2x-y)-4(2x 3y)? （x-y)^2+2(x-y)-8怎么化简?为什么等于（x-y+4)(x-y-2)? 怎么化简（x-y+4xy/x-y）（x+y-4xy/x+y）（/是分数线） 高数中偏导数的问题求函数Z=(X*X*Y*Y)/(X-Y）对自变量X的偏导数怎么做啊?书上是这么写的.将Y看成常数,对X求导,得【2X*Y*Y（X-Y）-X*X*Y*Y】/(X-Y)(X-Y)在化简一下就是【X*X*Y*Y-2X*Y*Y*Y】/(X-Y)(X-Y)我想问 [3x^2-(x+y)(y-x)][2(-x-y)(y-x)+2x^2+3y^2]怎么化简? 3x^2+5xy-2y^2+x+9y-4怎么化简 10X+10Y=10Y+X+9怎么化简 3x+2=y 5x+4=y 7x+6=y 9x+8=y 11x=y怎么解 (x/x+y-x/y-x-2xy/x.x-y.y)/(1/x-1/y) 分式化简 x²y+2xy-3y怎么化简