(1).(x-2y)(x+2y)-(x+2y)^2(2).(2a+1)^2-(1-2a)^2(3).(3x-y)^2-(2x+y)^2+5x(y-x)

x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2 [(-x-y)(-x+y)-(x+y)^2-x(y-y^2)}÷1/2y 化简y(x+y)+(x+y)(x-y)-x^2 因式分解x(x+y)(x-y)-x(x+y)^2 1、y-x/x²-y²2、(x-y)(y-z)(z-x)/(z-y)(y-x)(x-z) (x+y)(x-y)-(x-y)^2如题 (x+y)(x-y)-(x-y)^2 (x/x+y-x/y-x-2xy/x.x-y.y)/(1/x-1/y) 分式化简 (x-y)(2x-y-1) 【2(x-y)(x-y)(x-y)-8(x-y)(x-y)(x+y)+6y(x-y)(x-y)]/2(x-y)(x-y) x²/xy-x/y 3x/4x+y - x-2y/4x+y (1-y/y+x)÷x/y²-x² x^2(x-y)+(y-x) x(x-y)2-(y-x)3 已知x+y=a,2x-y=-2a,求[（x/y-y/x)/(x+y)-x(1/x-1/y)]/[(x+1)/y]的值 若2/x-1/y=3,求[y/x-y/x-y(x-y/x-x+y)]/x-2y/x的值 2y(x+二分之一y)-[(x+y)(x-y)+2y(y+x)],其中|x-1|=2 （x-y)(x+y)-(x+y)^2+2y(y-x),其中x=1,y=3. 计算:y-x分之x+y+x-y分之y-y-x分之2x-y 【(x-y)^2+(x+y)(x-y)】除以 2x