Помогите пожалуйста 799 номер

а) $1 \frac{1}{4}- \frac{1}{2}= \frac{5}{4}- \frac{2}{4} = \frac{3}{4}$
б) $2 \frac{1}{2} - \frac{2}{3}= \frac{5}{2}- \frac{2}{3}= \frac{15}{6}- \frac{4}{6}= \frac{11}{6}= 1 \frac{5}{6}$
в) $3 \frac{2}{3}- 2\frac{4}{5}= \frac{11}{3}- \frac{14}{5}= \frac{55}{15}- \frac{42}{15}= \frac{13}{15}$
г) $2 \frac{3}{4} - 1 \frac{5}{6} = \frac{11}{4} - \frac{11}{6}= \frac{66}{24}- \frac{44}{24}= \frac{22}{24}= \frac{11}{12}$