1) \frac{2x}{4x^2-y^2} - \frac{1}{2x+y} - \frac{y}{4x^2-y^2} =

\frac{2x}{4x^2-y^2} - \frac{1}{2x+y} - \frac{y}{4x^2-y^2} = \frac{2x - y}{4x^2-y^2} - \frac{1}{2x+y} = \frac{2x - y}{(2x-y)(2x+y)} - \frac{1}{2x+y} = \frac{1}{2x+y} - \frac{1}{2x+y} = 0