Đáp án: `x ∈ { 5/2 ; (-2)/3 }`
Giải thích các bước giải:
`|5x - 3| - x = 7`
`⇔ |5x - 3| = 7 + x`
`⇔` \(\left[ \begin{array}{l}5x - 3 = 7 + x\\5x - 3 = -(7 + x)\end{array} \right.\)
`⇔` \(\left[ \begin{array}{l}5x - x = 7 + 3\\5x - 3 = -7 - x\end{array} \right.\)
`⇔` \(\left[ \begin{array}{l}4x = 10\\5x + x = -7 + 3\end{array} \right.\)
`⇔` \(\left[ \begin{array}{l}x = 10 : 4 = \frac{5}{2}\\6x = -4\end{array} \right.\)
`⇔` \(\left[ \begin{array}{l}x = \frac{5}{2}\\x = (-4) : 6 = \frac{-2}{3}\end{array} \right.\)
Vậy `x ∈ { 5/2 ; (-2)/3 }`
