已知x(x+y)-2y(x+3y)=0(xy不得0）,求x平方+y平方比xy的值

已知:3x-5y=0,求x/y,x-y/y,x-y/x 已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y) 已知x-y=3,求[（x+y)(x-y)-(x-y)^2+2y(x-y)]除以的值 已知3x =2y 求x/x+y+y/x-y-y²/x²-y² 已知|x+y-3|+(x-y)2=0则 已知x-3y=0,求(2x+y)/(x^2-2xy+y^2)X(x-y) 已知x>0,Y>0,如何证x^2/y+y^2/x>=x+y 已知|3x-y|+|x+y|=0,求x-y除以x*y的值. 已知|x|=2,|y|=3,|x+y|=-(x+y)求x-y 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*x-4xy+4y*y=0 求[2x(x+y)-y(x+y)]/(4x*x-4xy+y*y)的值? 已知x*x+4x+y*y-2y+5=0,则x*x+y*y=? 已知X*X+Y*Y+6X-8Y+25=0 求（Y/X)+(X/Y)-2=? 已知2y-x=-3,求[4y(2x-y)-2x(2x-y)]/(2x-y 已知2x-3y=0则3x-y比x+2y= 已知x^2-3xy+2y^2=0 则x/y+x/y= 已知3x-4y=0,则x^2-y^2/x^2+y^2 已知x+y=0,求x^3+x^2*y+xy^2+y^3