Đáp án:
Giải thích các bước giải:
`a) |2x - 6| - x = 5x + 2`
`|2x - 6| = 6x + 2`
$\begin{cases} 6x + 2 ≥ 0\\\left[ \begin{array}{l}2x - 6 = 6x + 2\\2x - 6 = -6x - 2\end{array} \right. \end{cases}$
$\begin{cases} x ≥ \dfrac{-1}{3}\\\left[ \begin{array}{l}4x = -4\\8x = 0\end{array} \right. \end{cases}$
$\begin{cases} x ≥ \dfrac{-1}{3}\\\left[ \begin{array}{l}x = -1 ( L )\\x = 0 ( TM )\end{array} \right. \end{cases}$
`b) |2x-5| = 5`
`2x - 5 = ± 5`
\(\left[ \begin{array}{l}2x=0\\2x=-10\end{array} \right.\)
\(\left[ \begin{array}{l}x=0\\x=-5\end{array} \right.\)
`c) |-2x| + x = 5x + 3`
`|-2x| = 4x + 3`
`4x + 3 ≥ 0`
`x ≥ \frac{-3}{4}`
`-2x = 4x + 3`
`-6x = 3`
`x = \frac{-1}{2} ( TM )`
`-2x = -4x - 3`
`2x = -3`
`x = \frac{-3}{2} ( L )`