Theo đề bài ta có:
\(\frac{x-1}{2}=\frac{y-2}{3}=\frac{z-3}{4}\) và 2x + 3y - z = 50
Áp dụng tính chất của dãy tỉ số bằng nhau ta có:
\(\frac{x-1}{2}=\frac{y-2}{3}=\frac{z-3}{4}=\frac{2x-2}{4}=\frac{3y-6}{9}=\frac{z-3}{4}\) \(=\frac{2x-2+3y-6-\left(z-3\right)}{4+9-4}=\frac{2x-2+3y-6-z+3}{10}\) \(=\frac{2x+3y-z-5}{10}=\frac{50-5}{10}=\frac{45}{10}=4,5\)
\(\Rightarrow\left[\begin{array}{nghiempt}x-1=9\\y-2=13,5\\z-3=18\end{array}\right.\) \(\Rightarrow\left[\begin{array}{nghiempt}x=10\\y=15,5\\z=21\end{array}\right.\)
Vậy.......................
\(\frac{x-1}{2}=\frac{y-2}{3}=\frac{z-3}{4}\)
\(\Rightarrow\frac{2\left(x-1\right)}{4}=\frac{3\left(y-2\right)}{9}=\frac{z-3}{4}\)
\(\Rightarrow\frac{2x-2}{4}=\frac{3y-6}{9}=\frac{z-3}{4}\)
Áp dụng tính chất dãy tỉ số bằng nhau, ta có:\(\frac{2x-2}{4}=\frac{3y-6}{9}=\frac{z-3}{4}=\frac{\left(2x-2\right)+\left(3y-6\right)-\left(z-3\right)}{4+9-4}=\)
\(\frac{2x-2+3y-6-z+3}{9}=\frac{2x+3y-z-\left(2+6-3\right)}{9}\)
\(=\frac{50-5}{9}=\frac{45}{9}=5\)
Do đó: \(\frac{x}{2}=5\Rightarrow x=5.2=10\)
\(\frac{y}{3}=5\Rightarrow y=5.3=15\)
\(\frac{z}{4}=5\Rightarrow z=5.4=20\)
Vậy \(x=10\), \(y=15\), \(z=20\)