1. Выполните действия: а) 4/115 - 5; б) 5/14 - 2/15; в) 3/26 - 1 1/12; г) 4/31 - 28/93; д) 16/13 - 12/13; e) 3 2/3 - 11/12.

а) $$ \frac{4}{115} - 5 = \frac{4}{115} - \frac{5 \cdot 115}{115} = \frac{4 - 575}{115} = \frac{-571}{115} = -4 \frac{111}{115} $$

б) $$ \frac{5}{14} - \frac{2}{15} = \frac{5 \cdot 15}{14 \cdot 15} - \frac{2 \cdot 14}{15 \cdot 14} = \frac{75}{210} - \frac{28}{210} = \frac{47}{210} $$

в) $$ \frac{3}{26} - 1 \frac{1}{12} = \frac{3}{26} - \frac{13}{12} = \frac{3 \cdot 6}{26 \cdot 6} - \frac{13 \cdot 13}{12 \cdot 13} = \frac{18}{156} - \frac{169}{156} = \frac{-151}{156} $$

г) $$ \frac{4}{31} - \frac{28}{93} = \frac{4 \cdot 3}{31 \cdot 3} - \frac{28}{93} = \frac{12}{93} - \frac{28}{93} = \frac{-16}{93} $$

д) $$ \frac{16}{13} - \frac{12}{13} = \frac{16-12}{13} = \frac{4}{13} $$

е) $$ 3 \frac{2}{3} - \frac{11}{12} = \frac{11}{3} - \frac{11}{12} = \frac{11 \cdot 4}{3 \cdot 4} - \frac{11}{12} = \frac{44}{12} - \frac{11}{12} = \frac{33}{12} = \frac{11}{4} = 2 \frac{3}{4} $$

Ответ: а) -4 111/115; б) 47/210; в) -151/156; г) -16/93; д) 4/13; е) 2 3/4