Đáp án:
\(x = \dfrac{{19}}{{10}}\)
Giải thích các bước giải:
\(\begin{array}{l}
\left| {x - \dfrac{{17}}{{10}}} \right| = \left| {x - \dfrac{{21}}{{10}}} \right|\\
\to \left[ \begin{array}{l}
x - \dfrac{{17}}{{10}} = x - \dfrac{{21}}{{10}}\\
x - \dfrac{{17}}{{10}} = - x + \dfrac{{21}}{{10}}
\end{array} \right.\\
\to \left[ \begin{array}{l}
- \dfrac{{17}}{{10}} = - \dfrac{{21}}{{10}}\left( {vô lý} \right)\\
2x = \dfrac{{38}}{{10}}
\end{array} \right.\\
\to x = \dfrac{{19}}{{10}}
\end{array}\)