\( \frac{7}{9} + \frac{5}{18} = \frac{7 \cdot 2}{9 \cdot 2} + \frac{5}{18} = \frac{14}{18} + \frac{5}{18} = \frac{14 + 5}{18} = \frac{19}{18} = 1\frac{1}{18} \)
\( 7\frac{2}{3} + 4\frac{4}{5} = 7 + \frac{2}{3} + 4 + \frac{4}{5} = (7+4) + (\frac{2}{3} + \frac{4}{5}) = 11 + (\frac{2 \cdot 5}{3 \cdot 5} + \frac{4 \cdot 3}{5 \cdot 3}) = 11 + (\frac{10}{15} + \frac{12}{15}) = 11 + \frac{10 + 12}{15} = 11 + \frac{22}{15} = 11 + 1\frac{7}{15} = 12\frac{7}{15} \)
\( 6\frac{7}{24} + 2\frac{5}{16} = (6+2) + (\frac{7}{24} + \frac{5}{16}) = 8 + (\frac{7 \cdot 2}{24 \cdot 2} + \frac{5 \cdot 3}{16 \cdot 3}) = 8 + (\frac{14}{48} + \frac{15}{48}) = 8 + \frac{14 + 15}{48} = 8 + \frac{29}{48} = 8\frac{29}{48} \)