已知2x=3y,求(xy/x^2+y^2)-(y^2/x^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
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xy=2,x-y=3,求(x+y)(x-y)-y^2-(6x^2y-2xy^2)/2y的值.
已知x-3y=0,求2x+y/x-2xy+y乘(x-y)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/xy=3,求分式2x+3xy-2y/x-2xy-y的值.
已知X+Y=3XY,求2X+2Y-XY除以X+Y+2XY的值,要算理.
已知x-y=4xy,求x-2xy-y分之2x+3xy-2y的值!