Tìm x, biết: a)|2x+3|=5 b) |2x-1|=|2x+3| c)|x-1|+3x=1 d)|5x-3|-x=7

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1. $\begin{array}{l}
   a)\,\,\,\,\left| {2x + 3} \right| = 5\\
   \Rightarrow \left[ \begin{array}{l}
   2x + 3 = 5\\
   2x – 3 = 5
   \end{array} \right. \Rightarrow \left[ \begin{array}{l}
   2x = 2\\
   2x = 8
   \end{array} \right. \Rightarrow \left[ \begin{array}{l}
   x = 1\\
   x = 4
   \end{array} \right.\\
   b)\,\,\,\left| {2x – 1} \right| = \left| {2x + 3} \right|\\
   \Rightarrow \left[ \begin{array}{l}
   2x – 1 = 2x + 3\\
   2x – 1 = – 2x – 3
   \end{array} \right. \Rightarrow \left[ \begin{array}{l}
   2x – 2x = 3 + 1\\
   2x + 2x = – 3 + 1
   \end{array} \right.\\
   \Rightarrow \left[ \begin{array}{l}
   0x = 4\,\,(vo\,\,li)\\
   4x = – 2\,\,\,
   \end{array} \right. \Rightarrow x = \dfrac{{ – 1}}{2}
   \end{array}$

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