Б: 3/7 + 2/7 =; 7/10 + 2/10 =; 13/15 − 6/15 =; 8/11 + 3/11 =; 23/100 − 10/100 =.

1. \(\frac{3}{7}+\frac{2}{7}=\frac{5}{7}\)
2. \(\frac{7}{10}+\frac{2}{10}=\frac{9}{10}\)
3. \(\frac{13}{15}-\frac{6}{15}=\frac{7}{15}\)
4. \(\frac{8}{11}+\frac{3}{11}=\frac{11}{11}=1\)
5. \(\frac{23}{100}-\frac{10}{100}=\frac{13}{100}\)

Ответ: \(\frac{5}{7};\ \frac{9}{10};\ \frac{7}{15};\ 1;\ \frac{13}{100}\).