Đặt :
\(\frac{x-4}{2}=\frac{y-6}{3}=\frac{z-8}{4}=k\)
\(\hept{\begin{cases}x-4=2k\\y-6=3k\\z-8=4k\end{cases}\Leftrightarrow\hept{\begin{cases}x=2k+4\\y=3k+6\\z=4k+8\end{cases}}}\)
\(\Rightarrow3x+2y-3z=36\Leftrightarrow3\left(2k+4\right)+2\left(3k+6\right)-3\left(4k+8\right)=36\)
\(\Leftrightarrow6k+4+6k+6-12k+8=36\)
\(\Leftrightarrow6k+4+6k+6-6k.2+8=36\)
\(\Leftrightarrow6\left[k\left(4+6-8\right)\right].2=36\)
\(\Leftrightarrow6k.2.2=36\Leftrightarrow6k.2^2=36\)
\(\Leftrightarrow6k=9\)
\(\Rightarrow k=\frac{3}{2}\)
\(\Rightarrow\hept{\begin{cases}x=\frac{3}{2}.2+4\\y=\frac{3}{2}.3+6\\z=\frac{3}{2}.4+8\end{cases}\Leftrightarrow\hept{\begin{cases}x=3+4\\y=\frac{9}{2}+6\\z=6+8\end{cases}\Leftrightarrow}\hept{\begin{cases}x=7\\y=\frac{21}{2}\\z=14\end{cases}}}\)
Vậy \(\hept{\begin{cases}x=7\\y=\frac{21}{2}\\z=14\end{cases}}\)
Nhớ k nha ,dù mk trả lời hơi muộn
