а) 3/4 + a + 5/8 = 2 1/8; б) (a − 1 18/19) − 11/38 = 2; в) x + 7/12 = 1/3 + 5/6; г) (18 6/7 + y) − 12 2/3 = 8 1/7; д) (12 21/32 + x) − 4 5/8 = 13 1/16; е) 3/4 + (10 27/40 + a) = 15 3/40; ж) (x − 4 5/7) + 9/14 = 1; з) 100 − (x + 99 2/5) = 3/10; и) 8/17 + (x + 1 1/34) = 5 1/2; к) (12/25 + x) + 18/50 = 2 17/50

а) \(a=2\frac{1}{8}-\frac{3}{4}-\frac{5}{8}=\frac{17}{8}-\frac{6}{8}-\frac{5}{8}=\frac{3}{4}\).

б) \(a=2+1\frac{18}{19}+\frac{11}{38}=3+\frac{36}{38}+\frac{11}{38}=4\frac{9}{38}\).

в) \(x=\frac{1}{3}+\frac{5}{6}-\frac{7}{12}=\frac{4}{12}+\frac{10}{12}-\frac{7}{12}=\frac{7}{12}\).

г) \(y=8\frac{1}{7}+12\frac{2}{3}-18\frac{6}{7}=2\frac{23}{21}=3\frac{2}{21}\).

д) \(x=13\frac{1}{16}+4\frac{5}{8}-12\frac{21}{32}=5\frac{1}{32}\).

е) \(a=15\frac{3}{40}-\frac{3}{4}-10\frac{27}{40}=3\frac{6}{40}=3\frac{3}{20}\).

ж) \(x=1+4\frac{5}{7}-\frac{9}{14}=5\frac{1}{14}\).

з) \(x=100-99\frac{2}{5}-\frac{3}{10}=\frac{3}{10}\).

и) \(x=5\frac{1}{2}-\frac{8}{17}-1\frac{1}{34}-\frac{8}{17}=3\frac{1}{34}\).

к) \(x=2\frac{17}{50}-\frac{12}{25}-\frac{18}{50}=1\frac{1}{50}\).

Ответ: а) 3/4; б) 4 9/38; в) 7/12; г) 3 2/21; д) 5 1/32; е) 3 3/20; ж) 5 1/14; з) 3/10; и) 3 1/34; к) 1 1/50.