Đáp án:
\[x = 5\]
Giải thích các bước giải:
Ta có:
\(\begin{array}{l}
\frac{{x - 1}}{2} + \frac{{x - 1}}{4} = \frac{{1 + 2\left( {x - 1} \right)}}{3}\\
\Leftrightarrow \frac{{x - 1}}{2} + \frac{{x - 1}}{4} = \frac{1}{3} + \frac{{2\left( {x - 1} \right)}}{3}\\
\Leftrightarrow \frac{{x - 1}}{2} + \frac{{x - 1}}{4} - \frac{{2\left( {x - 1} \right)}}{3} = \frac{1}{3}\\
\Leftrightarrow \left( {x - 1} \right)\left( {\frac{1}{2} + \frac{1}{4} - \frac{2}{3}} \right) = \frac{1}{3}\\
\Leftrightarrow \left( {x - 1} \right).\frac{1}{{12}} = \frac{1}{3}\\
\Leftrightarrow \left( {x - 1} \right) = 4\\
\Leftrightarrow x = 5
\end{array}\)
