[tex]6 \frac{8}{15} - 3 \frac{2}{5} = 6 \frac{8}{15} - 3 \frac{6}{15} = 3 \frac{2}{15} [/tex]
[tex]1 \frac{6}{5} + \frac{8}{11} = 1 \frac{66}{55} + \frac{40}{55} = 1 \frac{106}{55} = 2 \frac{51}{55} [/tex]
[tex]1 \frac{3}{11} - \frac{9}{11} = \frac{14}{11} - \frac{9}{11} = \frac{5}{11} [/tex]
[tex]4 \frac{1}{6} \div 1 \frac{2}{3} = \frac{25}{6} \div \frac{5}{3} = \frac{25}{6} \times \frac{3}{5} = \frac{5}{2} \times \frac{1}{1} = \frac{5}{2} = 2 \frac{1}{2} [/tex]
