B3:
\(\left\{{}\begin{matrix}P+N+E=52\\\left(P+E\right)-N=16\\P=Z=E\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}2P+N=52\\2P-N=16\end{matrix}\right.\\ \Leftrightarrow\left\{{}\begin{matrix}P=E=Z=17\\N=18\end{matrix}\right.\)
B4:
\(\left\{{}\begin{matrix}P+E+N=28\\P=E=Z\\\left(P+E\right)=35,7\%.28=10\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}N=18\\P=E=Z=5\end{matrix}\right.\)
Em xem lại đề.
Bài 3
\(\left\{{}\begin{matrix}P+N+E=52\\\left(P+E\right)-N=16\\P=Z=E\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}2P+N=52\\2P-N=16\end{matrix}\right.\)
\(\Leftrightarrow\left\{{}\begin{matrix}P=E=Z=17\\N=18\end{matrix}\right.\)
Bài 4
\(\left\{{}\begin{matrix}P+E+N=28\\P=E=Z\\\left(P+E\right)=35,7\%.28=10\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}N=18\\P=E=Z=5\end{matrix}\right.\)
đề hơi sai
