x+y=5,2x+y=8,x-2y=0,3x+2y=8

x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2 x*x+2x+y*y-4y+5=0 x= y= 已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y) 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 已知X*X+Y*Y+6X-8Y+25=0 求（Y/X)+(X/Y)-2=? 已知x*x+4x+y*y-2y+5=0,则x*x+y*y=? x*x+2x-y*y+6y-8=0,x+y不等于2,求x-y的值 {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 【2(x-y)^3-8(x-y)^2(x+y)+6y(x-y)^2】/2(x-y)^2= x+y=5,2x+y=8,x-2y=0,3x+2y=8 （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 (4x-2y-z)-{5x[8y-2y-(x+y)]-x+(3y-10z)]=? kuaihuajian x+5y+2=0,则4^2x+y*8^y-x 已知|5x-y-8|+(7y-x+2)=0则4x+6y 已知x^2+4y^2-2x-2x+8y+5=0,求x^2-y^2/2x^2+xy-y^2*2y-y/xy-y/(x^2+y^2/y)^2的值 先化简,再求值 [2/3x - 2/x+y（x+y/3x -x-y）]*x/x-y,其中5x+3y=0 先化简,再求值:[3x-2/x+y(x+y/3x-x-y)]/(x-y/x),其中5x+3y=0