1.(3X^2+1/2y-2/3y^2)(-1/2XY)^3 2、3(X-2Y)^2-27(3X+Y)^2
3y/2x+2y+2xy/x²+xy 2x/x²-64y²-1/x-8y (1/a+1/b
1、(-7x^y)(2x^y-3xy^3+xy) 2、((x-y)^6)/((y-x)^3)/(x-y)
(x+2y-3xy)-(-2x-y+xy),其中x+y=,xy=-,求值.
已知x-y=1,y≠0,求{(x+2y)²+(2x+y)(x+4y)-3(x+y)(x-y)}÷y的值.
xy(xy+1)+(xy+3)-2(x+y+2分之一)-(x+y-1)的平方
(x+y)(x-y)-(2xy+3y)平方
[x(x^2y^2-xy)-y(x^2-x^3y)]/3x^2y
x(x-1)-(x平方-y)=-3,求x平方+y平方-2xy
【(x-y)^3(x^1/2+y^1/2)^-3+3(x根号y-y根号x)】/(x根号x+y根号y)+(2xy根号xy-
(1)3xy×(-4xy+2xy-1)(2)(x+2y)(3x-2y)+(x-2y)(3x+2y)
1/x-1/y=2 求(2x+3xy-2y)/(x-xy-y)的值
1/x-1/y=4,求分式(3x+xy-3y)/(x-2xy-y)