\[\frac{3x}{x^{3} - 1} - \frac{4x - 1}{1 - x^{3}} - \frac{x^{2}}{1 - x^{3}} =\]
\[= \frac{- 3x}{1 - x^{3}} - \frac{4x - 1}{1 - x^{3}} - \frac{x^{2}}{1 - x^{3}} =\]
\[= \frac{- 3x - 4x + 1 - x^{2}}{1 - x^{3}} =\]
\[= \frac{- x^{2} - 7x + 1}{1 - x^{3}} = \frac{x^{2} + 7x - 1}{x63 - 1}\]