`x:3+x:4+x:12=6`
`x xx(1)/(3)+x xx(1)/(4)+x xx(1)/(12)=6`
`x xx((1)/(3)+(1)/(4)+(1)/(12))=6`
`x xx(4+3+1)/(12)=6`
`x xx(8)/(12)=6`
`x xx (2)/(3)=6`
`x =6:(2)/(3)=9`
\(x.\dfrac{1}{3}+x.\dfrac{1}{4}+x.\dfrac{1}{12}=6\)
\(x.\left(\dfrac{1}{3}+\dfrac{1}{4}+\dfrac{1}{12}\right)=6\)
\(x.\dfrac{2}{3}=6\)
\(x=6:\dfrac{2}{3}\)
\(x=9\)
x:3+x:4+x:12=6
=>x:(3+4+12)=6
=>x:19=6
=>x=19x6
=>x=114
Vậy x=114
X÷3+x÷4+x÷12=6
=>x÷(3+4+12)=6
=>x÷19=6
=>x=6×19
=>x=114
Vậy x=114