数学题(较难)若2x-3y=0,求1/2xy/(x^2+y^2)-y^2/(2x^2-y^2)的值.
数学题(较难)若2x-3y=0,求1/2xy/(x^2+y^2)-y^2/(2x^2-y^2)的值.
已知x*x-4xy+4y*y=0 求[2x(x+y)-y(x+y)]/(4x*x-4xy+y*y)的值?
已知3x*+xy-2y*=0,求(x/y)-(y/x)-(x*+y*)/(xy)的值.*是平方
若x+y-5xy=0,求(2x-3xy+2y)/(x+2xy+y)的值
若x-y=4,xy=1,求(-2xy+2x+3y)-(3xy+2y-2x)-(x+4y+xy)的值
已知xy=2,x-y=3,求(x+y)(x-y)-y^2-(6x^2y-2xy^2)/2y的值.
已知xy=-2,x-y=3,求(x+y)(x-y)-y平方+(x-y)平方-(6x2y-2xy平方)/2y的值
已知x+y=-1,xy=-2,求代数式-5(x+y)+(x-y)+x(xy+y)的值
已知x-3y=0,求(2x+y)/(x^2-2xy+y^2)*(x-y)的值
已知x-3y=0,求(2x+y)/(x^2-2xy+y^2)*(x-y)的值.
已知x-3y=0,求(2x+y)(x-y)/x^2-2xy+y^2的值
已知x-3y=0,求2x+y/x-2xy+y乘(x-y)的值