Em tham khảo nha :
\(\begin{array}{l}
1)\\
B\\
A = p + n\\
Z = p = e\\
2)\\
A\\
p = e = 13\\
n = 27 - 13 = 14\\
3)\\
A\\
\left\{ \begin{array}{l}
2p + n = 40\\
2p - n = 12
\end{array} \right.\\
\Rightarrow p = 13,n = 14\\
A = p + n = 13 + 14 = 27\\
4)\\
\left\{ \begin{array}{l}
2p + n = 36\\
p - n = 0
\end{array} \right.\\
\Rightarrow p = 12;n = 12\\
a)\\
C\\
Z = p = 12\\
b)\\
B\\
A = p + n = 12 + 12 = 24\\
5)\\
A\\
\left\{ \begin{array}{l}
2p + n = 52\\
p + n = 35
\end{array} \right.\\
\Rightarrow p = 17;n = 18\\
Z = p = 17\\
6)\\
\\
1 \le \dfrac{n}{p} \le 1,5 \Rightarrow 1 \le \dfrac{{28 - 2p}}{p} \le 1,5\\
\Rightarrow 8 \le p \le 9,33\\
p = 9\\
\Rightarrow n = 28 - 18 = 10\\
A = 9 + 10 = 19\\
_9^{19}X\\
7)\\
B\\
8)\\
D\\
^{16}{O^{16}}O\\
^{16}{O^{17}}O\\
^{16}{O^{18}}O\\
^{17}{O^{17}}O\\
^{17}{O^{18}}O\\
^{18}{O^{18}}O
\end{array}\)
