Сложение и вычитание дробей. Вычислите: 1) 3/7 + 16/28; 2) 1/6 + 5/18; 3) 5/7 + 3/14; 4) 7/15 + 3/5; 5) 7/15 + 1/3; 6) 2/30 + 3/5; 7) 2/7 + 4/21; 8) 3/5 + 11/20; 9) 1/5 + 8/15; 10) 12/27 + 2/3.

1. \(\frac{3}{7}+\frac{16}{28}=\frac{3}{7}+\frac{4}{7}=\frac{7}{7}=1\).
2. \(\frac{1}{6}+\frac{5}{18}=\frac{3}{18}+\frac{5}{18}=\frac{8}{18}=\frac{4}{9}\).
3. \(\frac{5}{7}+\frac{3}{14}=\frac{10}{14}+\frac{3}{14}=\frac{13}{14}\).
4. \(\frac{7}{15}+\frac{3}{5}=\frac{7}{15}+\frac{9}{15}=\frac{16}{15}=1\frac{1}{15}\).
5. \(\frac{7}{15}+\frac{1}{3}=\frac{7}{15}+\frac{5}{15}=\frac{12}{15}=\frac{4}{5}\).
6. \(\frac{2}{30}+\frac{3}{5}=\frac{1}{15}+\frac{9}{15}=\frac{10}{15}=\frac{2}{3}\).
7. \(\frac{2}{7}+\frac{4}{21}=\frac{6}{21}+\frac{4}{21}=\frac{10}{21}\).
8. \(\frac{3}{5}+\frac{11}{20}=\frac{12}{20}+\frac{11}{20}=\frac{23}{20}=1\frac{3}{20}\).
9. \(\frac{1}{5}+\frac{8}{15}=\frac{3}{15}+\frac{8}{15}=\frac{11}{15}\).
10. \(\frac{12}{27}+\frac{2}{3}=\frac{4}{9}+\frac{6}{9}=\frac{10}{9}=1\frac{1}{9}\).

Ответ: 1) 1; 2) 4/9; 3) 13/14; 4) 1 1/15; 5) 4/5; 6) 2/3; 7) 10/21; 8) 1 3/20; 9) 11/15; 10) 1 1/9.