2.265 Выполните умножение: а) 3/7 * 2/3; б) 7/10 * 4/15; в) 15/16 * 10/11; г) 38/45 * 18/19; д) 12/25 * 5/16; e) 9/26 * 13/18.

Решим примеры по действиям: а) $$rac{3}{7} \times \frac{2}{3} = \frac{3 \times 2}{7 \times 3} = \frac{6}{21} = \frac{2}{7}$$ б) $$rac{7}{10} \times \frac{4}{15} = \frac{7 \times 4}{10 \times 15} = \frac{28}{150} = \frac{14}{75}$$ в) $$rac{15}{16} \times \frac{10}{11} = \frac{15 \times 10}{16 \times 11} = \frac{150}{176} = \frac{75}{88}$$ г) $$rac{38}{45} \times \frac{18}{19} = \frac{38 \times 18}{45 \times 19} = \frac{684}{855} = \frac{36 \times 19}{45 \times 19} = \frac{36}{45} = \frac{4}{5}$$ д) $$rac{12}{25} \times \frac{5}{16} = \frac{12 \times 5}{25 \times 16} = \frac{60}{400} = \frac{3 \times 20}{20 \times 20} = \frac{3}{20}$$ e) $$rac{9}{26} \times \frac{13}{18} = \frac{9 \times 13}{26 \times 18} = \frac{117}{468} = \frac{9 \times 13}{36 \times 13} = \frac{9}{36} = \frac{1}{4}$$

Ответ:

а) 2/7 б) 14/75 в) 75/88 г) 4/5 д) 3/20 e) 1/4