已知(x y)^2=10,(x-y)^2=6.求2xy与x^2+y^2的值

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f(x+y,y/x)=x^2-y^2,则f(x,y)= 已知|x|=2,|y|=3,|x+y|=-(x+y)求x-y 已知x≠y,x^2-x=y^2-y,求x+y的值. 已知x>0,Y>0,如何证x^2/y+y^2/x>=x+y 已知x+y=2,则(x+y)^2-10x-10y+25=___. 已知x+y=2,则（x+y)2次方-10x-10y+25= 已知x^2+2x+y^2-6y+10=0 求（x+y)^2 已知x+y=4,x^2+y^2=10,求(x-y)^2 已知x^2+y^2-2x+6y+10,则x+y=? 已知x+y=10,x^3+y^3=400,求x^2+y^2 已知x^2+6x+y^2+10y=-34 求x.y 已知x²+y²+2x-6y+10=0,则x+y= 已知：x²y²-2x+6y+10=0则x+y= 已知 x²-2x+y²+6y+10=0,则x+y=? 已知x²+y²+2x-6 y+10=0,则x+y=