\(\left\{{}\begin{matrix}2P_A+N_A=46\\2P_A-N_A=14\end{matrix}\right.\Rightarrow\left\{{}\begin{matrix}P_A=15\\N_A=16\end{matrix}\right.\)
\(\left\{{}\begin{matrix}2P_B+N_B=25\\P_B-N_B=-1\end{matrix}\right.\)\(\Rightarrow\left\{{}\begin{matrix}P_B=8\\N_B=9\end{matrix}\right.\)
\(\Rightarrow\%A=\frac{15\cdot2}{15\cdot2+8\cdot5}\cdot100=42.86\%\)
công thức mk ko nhớ lắm sai mong bạn thông cảm ạ