Simplify the expression. \( \frac{z^{2}+z x+2 z+2 x}{z+2} \) Select the correct choice below and fill in any answer boxes in your choice. A. \( \frac{z^{2}+z x+2 z+2 x}{z+2}=\square \) (Simplify your answer.) B. The expression cannot be simplified.

3. ( 3,1 ball) Bittadan ko'p sondagi mushuklar jami 221 ta sichqon yeyishdi. Agar har bir mushukning yegan sichqonlari soni teng va umumiy mushuklar sonidan ko'pligi ma'lum bo'lsa, mushuklar sonini aniqlang? \( \begin{array}{llll}\text { A) } 9 & \text { B) } 13 & \text { C) } 17 & \text { d) } 21\end{array} \)

Simplify by clearing parentheses and combining like terms. \( 6(x-5 a)-(6 x+5 a)= \)

Simplify by combining like terms. \( -7 y^{2}+16 y^{2}=\square \) \( \square \)

olve the linear system \( \begin{array}{l}3 x_{1}-x_{2}+x_{3}+2 x_{4}=-2 \\ \qquad x_{1}+2 x_{2}-x_{3}+x_{4}=1 \\ -x_{1}-3 x_{2}-2 x_{3}-4 x_{4}=-6\end{array} \)

Verifica se está certó \( 3^{\frac{3}{2}} \) röo s'uma solucáa da equaça \( \log _{3} x^{4}+\log _{x} 3^{21}=20 \)