1 \frac{1}{7}+1 \frac{3}{5} - 1 \frac{1}{4} : 1 \frac{1}{8} =
= \frac{8}{7} + \frac{8}{5} - \frac{5}{4} : \frac{9}{8} =
= \frac{8}{7} + \frac{8}{5} - \frac{5}{4} * \frac{8}{9} =
= \frac{8}{7} + \frac{8}{5} - \frac{10}{9} =
= \frac{8*45 + 8*63 - 10*35}{315} =
= \frac{360 + 504 - 350}{315} =
= \frac{514}{315} = 1 \frac{199}{315}
Ответ: 1 \frac{199}{315}