Đáp án:
d. \(\left[ \begin{array}{l}
x = 6\\
x = 8
\end{array} \right.\)
Giải thích các bước giải:
\(\begin{array}{l}
a.\left| {x - 2} \right| = 3\\
\to \left[ \begin{array}{l}
x - 2 = 3\\
x - 2 = - 3
\end{array} \right.\\
\to \left[ \begin{array}{l}
x = 5\\
x = - 1
\end{array} \right.\\
b.\left| {x + 1} \right| = \left| {2x + 3} \right|\\
\to \left[ \begin{array}{l}
x + 1 = 2x + 3\\
x + 1 = - 2x - 3
\end{array} \right.\\
\to \left[ \begin{array}{l}
x = - 2\\
3x = - 4
\end{array} \right.\\
\to \left[ \begin{array}{l}
x = - 2\\
x = - \frac{4}{3}
\end{array} \right.
\end{array}\)
\(\begin{array}{l}
c.\left| {3x} \right| = x + 6\\
\to \left[ \begin{array}{l}
3x = x + 6\\
3x = - x - 6
\end{array} \right.\\
\to \left[ \begin{array}{l}
2x = 6\\
4x = - 6
\end{array} \right.\\
\to \left[ \begin{array}{l}
x = 3\\
x = - \frac{3}{2}
\end{array} \right.\\
d.\left| {x - 5} \right| = 13 - 2x\\
\to \left[ \begin{array}{l}
x - 5 = 13 - 2x\\
x - 5 = - 13 + 2x
\end{array} \right.\\
\to \left[ \begin{array}{l}
3x = 18\\
x = 8
\end{array} \right.\\
\to \left[ \begin{array}{l}
x = 6\\
x = 8
\end{array} \right.
\end{array}\)
