Đáp án:
`=>` $\left[\begin{matrix}x = 53/30\\x = (-133/30)\end{matrix}\right.$
Giải thích các bước giải:
`|1/2 × x + 2/3| - 3/4 = 4/5`
`\1/2 × x + 2/3| = 4/5 + 3/4`
`|1/2 × x + 2/3| = 31/20`
`=>`
`=>` $\left[\begin{matrix}1/2 × x + 2/3=21/30\\1/2 × x + 2/3=(-21/30)\end{matrix}\right.$
`=>` $\left[\begin{matrix}1/2 × x = 53/60\\1/2 × x =(-133/60)\end{matrix}\right.$
`=>` $\left[\begin{matrix}x = 53/60 : 1/2\\x = (-133/60) : 1/2\end{matrix}\right.$
`=>` $\left[\begin{matrix}x = 53/30\\x = (-133/30)\end{matrix}\right.$
