2x-y=10 x+y=0 x=?y=?

[x(x-y)-y(x-y)+(x+y)(x-y)]÷2x其中x=2012 y=2013 设Z=X+Y,其中X,Y满足X+2Y>=0,X-Y 已知x*x-4xy+4y*y=0 求[2x(x+y)-y(x+y)]/(4x*x-4xy+y*y)的值? 已知2x-y=10,求[(x²+y²)-(x-y)²+2y(x-y)]/4y 已知X-Y/X+Y=3,求代数式2(x-y)/X+Y-3X+Y/X+Y 已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y) 已知x*x+4x+y*y-2y+5=0,则x*x+y*y=? 设x>1,y>0,若x^y+x^-y=2根号2,则x^y-x^-y等于 y'-2y=(e^x)-x y'+2y/x=x通解 变量x,y满足x-2y=0,x 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*