Giải:
`|3x + 5| = |x + 2|`
`->` \(\left[ \begin{array}{l}3x + 5 = x + 2\\3x + 5 = -(x + 2)\end{array} \right.\)
`->` \(\left[ \begin{array}{l}3x - x = 2 - 5 = -3\\3x + x = -2 - 5 = -7\end{array} \right.\)
`->` \(\left[ \begin{array}{l}2x = -3\\4x = -7\end{array} \right.\)
`->` \(\left[ \begin{array}{l}x = \dfrac{-3}{2}\\x = \dfrac{-7}{4}\end{array} \right.\)
Vậy `x ∈ { -3/2 ; -7/4 }`
