Ta có: \(\frac{x}{3}=\frac{y}{4};\frac{y}{5}=\frac{z}{7}\Rightarrow\frac{x}{15}=\frac{y}{20}=\frac{z}{28}\)
Mà \(2x+3y-z=372\)
\(\Rightarrow\frac{x}{15}=\frac{y}{20}=\frac{z}{28}=\frac{2x+3y-z}{30+60-28}=\frac{372}{62}=6\)
Vậy \(x=6.15=90\)
\(y=6.20=120\)
\(z=6.28=168\)
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