[latex] \frac{1}{13} *(2 \frac{3}{8} -1 \frac{5}{6} )*2 \frac{2}{5} + \frac{9}{10} [/latex]

[latex]1)2 \frac{3}{8} -1 \frac{5}{6} =2 \frac{9}{24} -1 \frac{20}{24} = \frac{13}{24} \\ 2) \frac{1}{13} * \frac{13}{24} = \frac{1}{24} \\ 3) \frac{1}{24} *2 \frac{2}{5} = \frac{1}{24} * \frac{12}{5} = \frac{1}{10} \\ 4) \frac{1}{10} + \frac{9}{10} = \frac{10}{10} =1[/latex]