5anty factorise: \( \begin{array}{ll}\text { a }-x^{2}-3 x+54 \\ \text { d }-x^{2}+2 x+48\end{array} \)

\( \frac{\frac{8}{5 x}-\frac{1}{x}}{\frac{4}{5}+\frac{3}{x}} \) \( \frac{\frac{8}{5 x}-\frac{1}{x}}{\frac{4}{5}+\frac{3}{x}}=\square( \) Simplify your answer. \( ) \)

Perform the indicated operation. \( \frac{8}{x^{2}-2 x-35}+\frac{7}{x-7} \) \( \frac{8}{x^{2}-2 x-35}+\frac{7}{x-7}=\square( \) Simplify your answer. \( ) \)

\( \frac{\frac{\frac{2}{x}}{\frac{2}{x^{2}}+\frac{7}{x}}}{\frac{\frac{2}{x}}{\frac{2}{x^{2}}+\frac{7}{x}}=\square \text { (Simplify your answer.) }} \)

Reste \( 2 x^{2}-7 x-1 \) de la suma de \( x^{2}+9 x-4 \) y \( -5 x^{2}-7 x+10 \)

Subtract. \[ \frac{3 x}{x^{2}-36}-\frac{2}{x+6} \]