Đáp án:
b) \(x = \dfrac{1}{2}\)
Giải thích các bước giải:
\(\begin{array}{l}
a)\left| {x - 5} \right| = \left| {x + 2} \right|\\
\to \left[ \begin{array}{l}
x - 5 = x + 2\\
x - 5 = - x - 2
\end{array} \right.\\
\to \left[ \begin{array}{l}
- 5 = 2\left( l \right)\\
2x = 3
\end{array} \right.\\
\to x = \dfrac{3}{2}\\
b)\left| {x - 1} \right| + \left| {x - 2} \right| = 1\\
\to \left[ \begin{array}{l}
x - 1 + x - 2 = 1\left( {DK:x \ge 2} \right)\\
x - 1 - x + 2 = 1\left( {DK:2 > x \ge 1} \right)\\
- x + 1 - x + 2 = 1\left( {DK:1 > x} \right)
\end{array} \right.\\
\to \left[ \begin{array}{l}
- 3 = 1\left( l \right)\\
1 = 1\left( {ld} \right)\\
- 2x = - 1
\end{array} \right.\\
\to x = \dfrac{1}{2}
\end{array}\)
