已知x^2+y^2-2x+2y-3=0和5x^2+5Y^2-x+7y-12=0关于直线l对称求l的方程要过程

已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y) 已知X和Y满足3X+4Y=2,X-Y-1/7 已知x和y满足3x+4y=2,x-y 已知|x+y-3|+(x-y)2=0则 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>0,Y>0,如何证x^2/y+y^2/x>=x+y 已知|x|=2,|y|=3,|x+y|=-(x+y)求x-y 已知X,Y,满足(X+3Y)(X-3Y)=-10(Y^2-6/5)和2X(Y-1)+4(1/2X-1)=0 （X+Y)^2 X^2Y+XY^2注：*/* 是分数 已知x-3y=0,求(2x+y)/(x^2-2xy+y^2)X(x-y) 已知|2X+3Y减2|+(2X+3Y+1)的平方=0,求X和Y? 已知|3x+2y-4|+√(2x-y-5)=0,求实数x和y的值 已知x=2/3y【xy不是0】,则x比y=【】比【】,x和y成【】比例 已知2y-x=-3,求[4y(2x-y)-2x(2x-y)]/(2x-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3x-4y=0,则x^2-y^2/x^2+y^2 已知x^2-3xy+2y^2=0 则x/y+x/y= 已知x*x+4x+y*y-2y+5=0,则x*x+y*y=?