\[6,625 - 3\frac{6}{17} = 6\frac{625}{1000} - 3\frac{6}{17} =\]
\[= 6\frac{5^{\backslash 17}}{8} - 3\frac{6^{\backslash 8}}{17} =\]
\[= 6\frac{85}{136} - 3\frac{48}{136} = 3\frac{37}{136}\]