已知:【(x^2+y^2)-(x-y)^2+2y(x-y)】÷4y=1,求4x/(4x^2×y^2)-1/(2x+y)的

已知4x=9y求(1)x+y/y (2)y-x/2x 已知x*x-4xy+4y*y=0 求[2x(x+y)-y(x+y)]/(4x*x-4xy+y*y)的值? 已知x=1/3,y=-1/2,求代数式x-(x+y)+(x+2y)-(x+3y)+(x+4y)-(x+5y)+...-( 已知x²+y²+5=2x+4y,求【2x²-(x-y)(x-y)】【(x+y-1)(x-y 已知2x-y=10,求[(x²+y²)-(x-y)²+2y(x-y)]/4y 已知x,y满足y^4+2x^4+1=4x^2y,求x,y的值 已知3x-4y/2x+y=1/2 求x/y的值 已知x/y=2,求2x(x+y)-y(x+y)/4x²-4xy+y² 2x-y=2,求[(x²+y²)-(x-y)²+2y(x-y)]÷4y 1、x(x-y)(x+y)-x(x+y)^2 已知x²+y²+5=2x+4y,求代数式（2x²-（x+y)(x-y))x((x+y-1) 已知2x+y=10,求代数式((x+y)的平方-(x-y)的平方-2y(x-1/2y))/4y的值