Toán Lớp 6: Tìm x : 1 . | 2X – 3,5 | = 6,5 2 . | 3X + 4/5 | – 1/2 = 0 3 . | 3/8 – 1/4 × X | = 1/4 Giúp với ạ

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1. 1.

   |2x – 3,5| = 6,5

   => \(\left[ \begin{array}{l}2x – 3,5 = 6,5\\x – 3,5 = -6,5\end{array} \right.\) 

   => \(\left[ \begin{array}{l}x=5\\x=-3\end{array} \right.\) 

   2.

   |3x – 4/5| – 1/2 = 0

   => |3x – 4/5| = 1/2

   => \(\left[ \begin{array}{l}3x – \dfrac{4}{5} = \dfrac{1}{2}\\3x – \dfrac{4}{5}= \dfrac{-1}{2}\end{array} \right.\) 

   => \(\left[ \begin{array}{l}x=\dfrac{13}{30}\\x=\dfrac{1}{10}\end{array} \right.\) 

   3.

   |3/8 – 1/4 × x| = 1/4

   => \(\left[ \begin{array}{l}\dfrac{3}{8} – \dfrac{1}{4} × x = \dfrac{1}{4}\\\dfrac{3}{8} – \dfrac{1}{4} × x = \dfrac{-1}{4}\end{array} \right.\) 

   => \(\left[ \begin{array}{l}x=\dfrac{1}{2}\\x=\dfrac{5}{2}\end{array} \right.\) 

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