求证x^3+y^3-3x^2y+xy^2≥0
(x-2xy)*(-xy+2y*y)-(3x*x-2xy)(x-9xy+6y*y)
求证不等式 x,y,z >0求证27*(x+y)^2*(y+z)^2*(z+x)^2大于等于64(xy+yz+xz)^3
(x+y)(x-y)-(2xy+3y)平方
已知3x*+xy-2y*=0,求(x/y)-(y/x)-(x*+y*)/(xy)的值.*是平方
已知3x^2+xy-2y^2=0,求{(x+y)/(x-y)+4xy/(y^2-x^2)}/{(x+3y)*(x-y)}
[x(x^2y^2-xy)-y(x^2-x^3y)]/3x^2y
1、(-7x^y)(2x^y-3xy^3+xy) 2、((x-y)^6)/((y-x)^3)/(x-y)
化简:x-y/x+3y÷x^-y^2/x^2+6xy+9y^2-(xy/x+y)
若x+y-5xy=0,求(2x-3xy+2y)/(x+2xy+y)的值
已知y-x-2xy=0,求3x+xy-3y/y-xy-x的值
已知y-x-2xy=0,求(3x+xy-3y)\(y-xy-x)的值
x^2-xy-6y^2+3xy+y+2