Đáp án: b. \(\left[ \begin{array}{l}x = – 2\\x = \dfrac{4}{5}\end{array} \right.\) Giải thích các bước giải: \(\begin{array}{l}a.\left| {x + 2} \right| – 3x + 3 = 1\\ \to \left| {x + 2} \right| = 3x – 2\\ \to \left[ \begin{array}{l}x + 2 = 3x – 2\\x + 2 = – 3x + 2\end{array} \right.\\ \to \left[ \begin{array}{l}2x = 4\\4x = 0\end{array} \right.\\ \to \left[ \begin{array}{l}x = 2\\x = 0\end{array} \right.\\b.2x – \left| {3x – 1} \right| = 3\\ \to \left| {3x – 1} \right| = 2x – 3\\ \to \left[ \begin{array}{l}3x – 1 = 2x – 3\\3x – 1 = – 2x + 3\end{array} \right.\\ \to \left[ \begin{array}{l}x = – 2\\5x = 4\end{array} \right.\\ \to \left[ \begin{array}{l}x = – 2\\x = \dfrac{4}{5}\end{array} \right.\end{array}\) Reply
Đáp án:
b. \(\left[ \begin{array}{l}
x = – 2\\
x = \dfrac{4}{5}
\end{array} \right.\)
Giải thích các bước giải:
\(\begin{array}{l}
a.\left| {x + 2} \right| – 3x + 3 = 1\\
\to \left| {x + 2} \right| = 3x – 2\\
\to \left[ \begin{array}{l}
x + 2 = 3x – 2\\
x + 2 = – 3x + 2
\end{array} \right.\\
\to \left[ \begin{array}{l}
2x = 4\\
4x = 0
\end{array} \right.\\
\to \left[ \begin{array}{l}
x = 2\\
x = 0
\end{array} \right.\\
b.2x – \left| {3x – 1} \right| = 3\\
\to \left| {3x – 1} \right| = 2x – 3\\
\to \left[ \begin{array}{l}
3x – 1 = 2x – 3\\
3x – 1 = – 2x + 3
\end{array} \right.\\
\to \left[ \begin{array}{l}
x = – 2\\
5x = 4
\end{array} \right.\\
\to \left[ \begin{array}{l}
x = – 2\\
x = \dfrac{4}{5}
\end{array} \right.
\end{array}\)