5. (a4-g9-13) Murod bilan llhomning pullari yig'indisi \( x \) so'm. Murod llhomga y so'm bersa, ularning pullari miqdori tenglashadi. Murodning necha so'm puli bor? \( \begin{array}{ll}\text { A) } \frac{x+3 y}{2} & \text { B) } \frac{x+y}{2} \\ \text { C) } \frac{x-y}{2} & \text { D) } \frac{x+2 y}{2}\end{array} \)

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

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

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.)

b) \( : \sqrt{x}=3 \)