\[\frac{3c^{2} - 2c + 4}{bc^{2}} - \frac{2c - 9^{\backslash c}}{\text{bc}} =\]
\[= \frac{3c^{2} - 2c + 4 - 2c^{2} + 9c}{bc^{2}} =\]
\[= \frac{c² + 7c + 4}{bc²}\]