\[3,7(2) = 3,7 + 0,02 + 0,002 + \ldots\]
\[q = 0,1;\ \ \]
\[S = \frac{0,02}{1 - 0,1} = \frac{0,02}{0,9} = \frac{1}{45}\]
\[3,7 + \frac{1}{45} = 3 + \frac{63 + 2}{90} =\]
\[= 3 + \frac{65}{90} = 3\frac{13}{18}\]
\[3,7(2) = 3\frac{13}{18}.\]