1) а) общий делитель; б) несократимой; в) разделить на их общий делитель.
2) Сократить можно дроби: \(\frac{2}{4},\ \frac{6}{8},\ \frac{6}{9},\ \frac{12}{24},\ \frac{36}{48},\ \frac{55}{88},\ \frac{42}{49}\).
3)
- \(\frac{2}{4}=\frac{2:2}{4:2}=\frac{1}{2}\);
- \(\frac{12}{16}=\frac{12:4}{16:4}=\frac{3}{4}\);
- \(\frac{32}{40}=\frac{32:8}{40:8}=\frac{4}{5}\);
- \(\frac{48}{72}=\frac{48:24}{72:24}=\frac{2}{3}\);
- \(\frac{6}{10}=\frac{6:2}{10:2}=\frac{3}{5}\);
- \(\frac{20}{21}\) — несократимая;
- \(\frac{28}{56}=\frac{28:28}{56:28}=\frac{1}{2}\);
- \(\frac{60}{96}=\frac{60:12}{96:12}=\frac{5}{8}\);
- \(\frac{3}{7}\) — несократимая;
- \(\frac{24}{36}=\frac{24:12}{36:12}=\frac{2}{3}\);
- \(\frac{48}{60}=\frac{48:12}{60:12}=\frac{4}{5}\);
- \(\frac{72}{90}=\frac{72:18}{90:18}=\frac{4}{5}\);
- \(\frac{6}{16}=\frac{6:2}{16:2}=\frac{3}{8}\);
- \(\frac{28}{40}=\frac{28:4}{40:4}=\frac{7}{10}\);
- \(\frac{40}{84}=\frac{40:4}{84:4}=\frac{10}{21}\);
- \(\frac{60}{100}=\frac{60:20}{100:20}=\frac{3}{5}\).