[4x/(4x^2-y^2)]-[1/(2x+y)]

1) (2x+5y)(2x-5y)(-4x^2-25y^2) 2) [（x+y)(x-y)-(x-y)^2+2y(x-y 1、x(x-y)(x+y)-x(x+y)^2 x^2-y^2/x+y-4x(x-y)+y^2/2x-y, （x+2)(x+3) (x-4)(x+1) (y+4)(y-2) (y-5)(y-3) 已知4x=9y求(1)x+y/y (2)y-x/2x {3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1 (2x-y)^2-4(x-y)(x+2y) (2x-y)²-4(x-y)(x+2y) 化简：（2x-y)²-4(x-y)(x+y) 1 4(x-y+1)+y(y-2x) 把4（x-y+1)+y(y-2x)因式分解 4(x-y+1)+y(y-2x)