(1) \( \frac{1}{4 x-2 y}-\frac{1}{y-2 x} \)

To simplify the expression \( \frac{1}{4 x-2 y}-\frac{1}{y-2 x} \), note that \( y - 2x \) can be rewritten as \(- (2x - y)\). Therefore, the expression becomes: \[ \frac{1}{4x - 2y} + \frac{1}{2x - y} \] Now, finding a common denominator, which is \((4x - 2y)(2x - y)\), we can rewrite the expression as: \[ \frac{(2x - y) + (4x - 2y)}{(4x - 2y)(2x - y)} \] Combining the terms in the numerator: \[ \frac{2x - y + 4x - 2y}{(4x - 2y)(2x - y)} = \frac{6x - 3y}{(4x - 2y)(2x - y)} \] Simplifying the numerator gives: \[ = \frac{3(2x - y)}{(4x - 2y)(2x - y)} \] Finally, we can cancel out \(2x - y\) from the numerator and denominator, leading us to: \[ = \frac{3}{4x - 2y} \] Thus, the simplified expression is: \[ \frac{3}{4x - 2y} \]