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Trả lời:
Bài 1:
$a, |2x|=x-6$ $(x \geq 6)$
\(⇔\left[ \begin{array}{l}2x=x-6\\2x=-x+6\end{array} \right.\) \(⇔\left[ \begin{array}{l}x=-6(Loại)\\x=2(Loại)\end{array} \right.\)
$b, |-3x|=x-8$ $(x \geq 8)$
\(⇔\left[ \begin{array}{l}-3x=x-8\\-3x=-x+8\end{array} \right.\) \(⇔\left[ \begin{array}{l}x=2(Loại)\\x=-4(Loại)\end{array} \right.\)
$c, |4x|=2x+12$ $(x \geq -6)$
\(⇔\left[ \begin{array}{l}4x=2x+12\\4x=-2x-12\end{array} \right.\) \(⇔\left[ \begin{array}{l}x=6\\x=-2\end{array} \right.\)
$d, |-5x|-16=3x$ $(x \geq -\dfrac{16}{3})$
\(⇔\left[ \begin{array}{l}-5x=3x+16\\-5x=-3x-16\end{array} \right.\) \(⇔\left[ \begin{array}{l}x=-2\\x=8\end{array} \right.\)
Bài 2:
$a, ||x-1|+2|=7$
\(⇔\left[ \begin{array}{l}|x-1|=-9(Loại)\\|x-1|=5\end{array} \right.\) \(⇔\left[ \begin{array}{l}x-1=5\\x-1=-5\end{array} \right.\) \(⇔\left[ \begin{array}{l}x=6\\x=-4\end{array} \right.\)
$b, |2-x|-|2x-3|=0$
$⇔|2-x|=|2x-3|$
\(⇔\left[ \begin{array}{l}2-x=2x-3\\2-x=-2x+3\end{array} \right.\) \(⇔\left[ \begin{array}{l}x=\dfrac{5}{3}\\x=1\end{array} \right.\).
