已知x=2007,y=2008,求x^2+2xy+y^2/5x^2-4xy除以x+y/5x-4y再+x^2-y/x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|=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+y=4,x^2-y^2=0,求x^2008-y^2007的值 已知x^2+y^2-2x+2y=-2,求代数式x^2007+y^2008的值 已知x^2+y^2-2x+2y=-2,求x^2007+y^2008的值 已知|x-1|+(y+1)^2=0,求x^2007+y^2008的值 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+y=a,2x-y=-2a,求[（x/y-y/x)/(x+y)-x(1/x-1/y)]/[(x+1)/y]的值 已知:x+2y=2011 求代数式{(x^+y^)-(x-y)^+2x(x+y)}/2x的值 已知x+y/x=11/8,求x-y/x+2y的值 已知2y-x=-3,求[4y(2x-y)-2x(2x-y)]/(2x-y 已知X*X+Y*Y+6X-8Y+25=0 求（Y/X)+(X/Y)-2=? 已知2/x+2/y=根号24,求 x/y(x-y) - y/x(x-y)的值 已知2/x 2/y=根号24,求 x/y(x-y) - y/x(x-y)的值 已知x/y=2,求2x(x+y)-y(x+y)/4x²-4xy+y² 已知:3x-5y=0,求x/y,x-y/y,x-y/x