Solve for \( x \) \[ \begin{array}{l}x(3 x-1)+7-x=2 x+3+9 x \\ \text { There is no solution. } \\ x=7 \\ x=7\end{array} \]

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

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

Simplify the following expression. \[ \frac{x+8 y}{x-2 y} \div\left(\frac{1}{8 y}-\frac{1}{x+8 y}\right) \] \( \frac{x+8 y}{x-2 y} \div\left(\frac{1}{8 y}-\frac{1}{x+8 y}\right)=\square \) (Simplify your answer.)

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

a) \( \quad x^{2}=49 \)