2x+5y+1=0 x=() y=()

x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2 （x+y-5)*（x+y-5)+（x-y+3)=0 x*x-y*y 已知:3x-5y=0,求x/y,x-y/y,x-y/x x*x+2x+y*y-4y+5=0 x= y= {6(x-y)-7(x+y)=21 {2(x-y)-5(x+y)=-1 (x-y)/(x+y)=3求( 3x-2y-1)/(x+y-5) {x+y=1 ,xy=-6{x(2x-3)=0,y=x²-1{(3x+4y-3)(3x+4y+3)=0,3x+2y=5{(x-y+2)(x+y)=0,x²+y²=8{(x+y)((x+y-1)=0,(x-y)(x-y-1)=0 若(x*x+y*y)(x*x+y*y)-4x*x*y*y=0,求代数式(x*x+5xy+y*y)/(x*x+2xy+y*y)的值 {(x+y)/2+(x-y)/3=1,(x+y)-5(x-y)=2.求x=?,y=? 已知x*x+4x+y*y-2y+5=0,则x*x+y*y=? 设x大于1,y大于0,x^y+x^-y=2根号二,x^y-x^-y等于? 已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y) 化简[(3x+4y)^2-(2x+y)(2x-y)+(-x+y)(5x-y)]除以-2y,其中x=-1,y=1 如果|x-2y+1|+|x+y-5|=0,那么x= ,y= |x-2y+1|+(x+y-5)²=0,则5x+4y= 3x+4y-5=0 x^2+y^2=1求x.y 如果|x-2y+1|+|2x-y-5|=0,则x+y=? x^2-x+y^2+2y+5/4=0 求x^-1+y^0