\(2x=5y=4z\)
\(\Leftrightarrow\frac{2x}{20}=\frac{5y}{20}=\frac{4z}{20}\)
\(\Leftrightarrow\frac{x}{10}=\frac{y}{4}=\frac{z}{5}\)
\(\Leftrightarrow\frac{x}{10}=\frac{y}{4}=\frac{5z}{25}\)
Áp dụng t,c dãy tỉ số bằng nhau ta có :
\(\frac{x}{10}=\frac{y}{4}=\frac{5x}{25}=\frac{x-y+5z}{10-4+25}=\frac{16}{31}=\frac{1}{2}\)
\(\Leftrightarrow\hept{\begin{cases}\frac{x}{10}=\frac{1}{2}\\\frac{y}{4}=\frac{1}{2}\\\frac{5z}{25}=\frac{1}{2}\end{cases}}\) \(\Leftrightarrow\hept{\begin{cases}x=5\\y=2\\x=2,5\end{cases}}\)