Giải:
\(123-5\left(x-4\right)=38\)
\(\Leftrightarrow5\left(x-4\right)=123-38\)
\(\Leftrightarrow5\left(x-4\right)=85\)
\(\Leftrightarrow x-4=\dfrac{85}{5}\)
\(\Leftrightarrow x-4=17\)
\(\Leftrightarrow x=17+4\)
\(\Leftrightarrow x=21\)
Vậy \(x=21\).
Chúc bạn học tốt!!!
