Ta phân tích:
`+)`$\dfrac{x}{6}$ = $\dfrac{z}{5}$`->` $\dfrac{x}{12}$ = $\dfrac{z}{10}$
`+)` $\dfrac{y}{4}$ = $\dfrac{z}{2}$ `->` $\dfrac{y}{20}$ = $\dfrac{z}{10}$
`=>` $\dfrac{x}{12}$=$\dfrac{y}{20}$=$\dfrac{z}{10}$
Áp dụng tính chất dãy tỉ số bằng nhau ta được:
$\dfrac{x}{12}$=$\dfrac{y}{20}$=$\dfrac{z}{10}$=$\dfrac{2x+3y-z}{24+60-10}$=$\dfrac{-148}{79}$=`-2`
Do đó, ta có:
`+)`$\dfrac{x}{12}$ = `-2` `=>` x= 12.(-2) = `-24`
`+)`$\dfrac{y}{20}$ = -2 `=>` y= 20.(-2) = `-40`
`+)`$\dfrac{z}{10}$ = -2 `=>` z= 10.(-2) = `-20`
Vậy `x` = `-24` ; `y` = `-40` ; `z` = `- 20`
