Komposisi Fungsi Menentukan g(x)

\begin{equation*}
\begin{split}
(f \circ g) (x) & = 5 - 3x \\\\
f(g(x)) & = 5 - 3x \\\\
2 \: g(x) - 1 & = 5 - 3x \\\\
2 \: g(x) & = 6 - 3x \\\\
g(x) & = 3 - 1 \tfrac 12 x
\end{split}
\end{equation*}