\( f(x)=-x^{2}+1 \) y \( g(x)=0,4 \)

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. \( ) \)

Simplify. \( \frac{\frac{3}{x+5}}{x-5}-\frac{3}{x^{2}-25} \) \( \frac{\frac{3}{x+5}}{\frac{3}{x-5}-\frac{3}{x^{2}-25}}=\square \) (Use integers or fractions for any numbers in the expression.)

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

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

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.)