3. Умножение и деление обыкновенных дробей 53610111921 1). . 2).= 3).·= 4).= 6207114238 25 4511721 5).= 6).· 7).:24= 8). 8:= 42072 631224 22 264 9). 10). 377

3. Умножение и деление обыкновенных дробей

1) \[\frac{5}{6} \cdot \frac{3}{20} = \frac{5 \cdot 3}{6 \cdot 20} = \frac{15}{120} = \frac{1}{8}\]

2) \[\frac{3}{7} \cdot \frac{6}{11} = \frac{3 \cdot 6}{7 \cdot 11} = \frac{18}{77}\]

3) \[\frac{6}{33} \cdot \frac{10}{11} = \frac{6 \cdot 10}{33 \cdot 11} = \frac{60}{363} = \frac{20}{121}\]

4) \[\frac{19}{42} \cdot \frac{21}{38} = \frac{19 \cdot 21}{42 \cdot 38} = \frac{399}{1596} = \frac{1}{2 \cdot 2} = \frac{1}{4}\]

5) \[\frac{4}{4} \div \frac{25}{72} = \frac{4}{4} \cdot \frac{72}{25} = \frac{4 \cdot 72}{4 \cdot 25} = \frac{288}{100} = \frac{72}{25}\]

6) \[\frac{21}{63} \cdot \frac{45}{72} = \frac{21 \cdot 45}{63 \cdot 72} = \frac{945}{4536} = \frac{5}{24}\]

7) \[\frac{7}{12} : 24 = \frac{7}{12} \div \frac{24}{1} = \frac{7}{12} \cdot \frac{1}{24} = \frac{7 \cdot 1}{12 \cdot 24} = \frac{7}{288}\]

8) \[8 : \frac{4}{22} = \frac{8}{1} \div \frac{4}{22} = \frac{8}{1} \cdot \frac{22}{4} = \frac{8 \cdot 22}{1 \cdot 4} = \frac{176}{4} = 44\]

9) \[\frac{2}{3} \div \frac{2}{7} = \frac{2}{3} \cdot \frac{7}{2} = \frac{2 \cdot 7}{3 \cdot 2} = \frac{14}{6} = \frac{7}{3}\]

10) \[\frac{6}{7} \cdot \frac{4}{22} = \frac{6 \cdot 4}{7 \cdot 22} = \frac{24}{154} = \frac{12}{77}\]