Đáp án:
`Ta có : (x-1)/2 = (y-2)/3 = (z-3)/4 `
`=> (x-1)/2 = (2(y-2))/6 = (3(z-3))/12`
`=> (x-1)/2 = (2y - 4)/6 = (3z-9)/12 = ((x-1)-(2y-4)+(3z+9))/(2-6+12)`
`= (1-2y+4+3z - 9)/(2-6+12) = (x-2y+3z-6) /8 = (14-6)/8 = 8/8 =1`
`=>` $\begin{cases}x-1=2\\y-2=3\\z-3=4\\\end{cases}$
`=>` $\begin{cases}x=3\\y=5\\z=7\\\end{cases}$
`~Go od luck !~`
