Đáp án + Giải thích các bước giải:
`428-|50-x+30|=350`
`=>|50-x+30|=428-350`
`=>|80-x|=78`
`=>` \(\left[ \begin{array}{l}80-x=78\\80-x=-78\end{array} \right.\)
`=>` \(\left[ \begin{array}{l}x=80-78\\x=80-(-78)\end{array} \right.\)
`=>` \(\left[ \begin{array}{l}x=2\\x=80+78\end{array} \right.\)
`=>` \(\left[ \begin{array}{l}x=2\\x=158\end{array} \right.\)
Vậy `x∈{2;158}`