39. Решите уравнения: а) x + 2/7 = 5/14; б) x − 1/4 = 6/11; в) 1/8 + b = 11/16; г) 4/15 − y = 7/30; д) 3/8 + a = 5/6; е) 7/12 − u = 8/84; ж) 5/13 + t = 7/10; з) 2/3 − b = 1/5; и) t − 1/6 = 11/42.

1. \(x=\frac{5}{14}-\frac{2}{7}=\frac{5}{14}-\frac{4}{14}=\frac{1}{14}\).
2. \(x=\frac{6}{11}+\frac{1}{4}=\frac{24+11}{44}=\frac{35}{44}\).
3. \(b=\frac{11}{16}-\frac{1}{8}=\frac{11}{16}-\frac{2}{16}=\frac{9}{16}\).
4. \(y=\frac{4}{15}-\frac{7}{30}=\frac{8}{30}-\frac{7}{30}=\frac{1}{30}\).
5. \(a=\frac{5}{6}-\frac{3}{8}=\frac{20-9}{24}=\frac{11}{24}\).
6. \(u=\frac{7}{12}-\frac{8}{84}=\frac{49}{84}-\frac{8}{84}=\frac{41}{84}\).
7. \(t=\frac{7}{10}-\frac{5}{13}=\frac{91-50}{130}=\frac{41}{130}\).
8. \(b=\frac{2}{3}-\frac{1}{5}=\frac{10-3}{15}=\frac{7}{15}\).
9. \(t=\frac{11}{42}+\frac{1}{6}=\frac{11}{42}+\frac{7}{42}=\frac{3}{7}\).

Ответ: а) \(\frac{1}{14}\); б) \(\frac{35}{44}\); в) \(\frac{9}{16}\); г) \(\frac{1}{30}\); д) \(\frac{11}{24}\); е) \(\frac{41}{84}\); ж) \(\frac{41}{130}\); з) \(\frac{7}{15}\); и) \(\frac{3}{7}\).