\[2c + 1 - \frac{5c^{2} - 1}{2c - 1} =\]
\[= (2c + 1)^{\backslash 2c - 1} - \frac{5c^{2} - 1}{2c - 1} =\]
\[= \frac{4c^{2} - 1 - 5c^{2} + 1}{2c - 1} =\]
\[= - \frac{c^{2}}{2c - 1} = \frac{c^{2}}{1 - 2c}.\]