[tex]1. \: \: 6 \frac{2}{3} + 3 \frac{4}{5} = \frac{20}{3} + \frac{19}{5} = \frac{100 + 57}{15} = \frac{157}{15} = 10 \frac{7}{15} [/tex]
[tex]2. \: \: 4 \frac{2}{3} - 2 \frac{4}{5} = \frac{14}{3} - \frac{14}{5} = \frac{70 - 42}{15} = \frac{28}{15} = 1 \frac{13}{15} [/tex]
[tex]3. \: \: 3 \frac{1}{2} + 1 \frac{1}{3} = \frac{7}{2} + \frac{4}{3} = \frac{21 + 8}{6} = \frac{29}{6} = 4 \frac{5}{6} [/tex]
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