(x+2y)(x-2y)-(2x-y)的平方-5y（五分之二x-y） 其中x=二分之一,y=-四分之一

x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2 (y-x)²(x-y)+(x-y)的三次方+2(x-y)²(y-x) 化简y(x+y)+(x+y)(x-y)-x^2 (x+y)(x-y)-(x-y)^2如题 (x+y)(x-y)-(x-y)^2 【2(x-y)(x-y)(x-y)-8(x-y)(x-y)(x+y)+6y(x-y)(x-y)]/2(x-y)(x-y) 因式分解x(x+y)(x-y)-x(x+y)^2 {(z+y)(x-y)-(x-y)的2次方+2y(x-y)}除以4y [(x-y)^2-(x+2y)(x-2y)]/y 计算:y-x分之x+y+x-y分之y-y-x分之2x-y x^2(x-y)+(y-x) x(x-y)2-(y-x)3 已知x-y=3,求[（x+y)(x-y)-(x-y)^2+2y(x-y)]除以的值 【(x-y)^2+(x+y)(x-y)】除以 2x [(x-y)²+(x+y)(x-y)]除以2x 若2/x-1/y=3,求[y/x-y/x-y(x-y/x-x+y)]/x-2y/x的值 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 [(x+2y)(x-2y)-(2x-y)²+(3x-y(2x-5y)]/(-x)的解答 [2/3x-2/x+y(x+y/3x-x-y)]/x-y/x