\[2,48 - 3\frac{3}{4} - 7\frac{1}{3} + 3,52 - 5\frac{1}{4} + 3\frac{7}{9} =\]
\[= (2,48 + 3,52) - \left( 3\frac{3}{4} + 5\frac{1}{4} \right) - \left( 7\frac{1^{\backslash 3}}{3} - 3\frac{7}{9} \right) =\]
\[= 6 - 8\frac{4}{4} - \left( 7\frac{3}{9} - 3\frac{7}{9} \right) =\]
\[= 6 - 9 - \left( 6\frac{12}{9} - 3\frac{7}{9} \right) =\]
\[= - 3 - 3\frac{5}{6} = - 6\frac{5}{9}.\]