№1 Вычислите:
a) $$\frac{4}{27} \cdot \frac{3}{32} = \frac{4 \cdot 3}{27 \cdot 32} = \frac{4 \cdot 3}{9 \cdot 3 \cdot 4 \cdot 8} = \frac{1}{9 \cdot 8} = \frac{1}{72}$$.
Ответ: $$\frac{1}{72}$$
г) $$3 \cdot \frac{4}{15} = \frac{3}{1} \cdot \frac{4}{15} = \frac{3 \cdot 4}{1 \cdot 15} = \frac{3 \cdot 4}{1 \cdot 3 \cdot 5} = \frac{4}{5}$$.
Ответ: $$\frac{4}{5}$$
ж) $$3\frac{3}{8} \cdot \frac{7}{5} = \frac{3 \cdot 8 + 3}{8} \cdot \frac{7}{5} = \frac{27}{8} \cdot \frac{7}{5} = \frac{27 \cdot 7}{8 \cdot 5} = \frac{189}{40} = 4\frac{29}{40}$$.
Ответ: $$4\frac{29}{40}$$
з) $$5\frac{1}{8} \cdot 1\frac{5}{27} = \frac{5 \cdot 8 + 1}{8} \cdot \frac{1 \cdot 27 + 5}{27} = \frac{41}{8} \cdot \frac{32}{27} = \frac{41 \cdot 32}{8 \cdot 27} = \frac{41 \cdot 4 \cdot 8}{8 \cdot 27} = \frac{41 \cdot 4}{27} = \frac{164}{27} = 6\frac{2}{27}$$.
Ответ: $$6\frac{2}{27}$$
в) $$\frac{19}{56} \cdot \frac{49}{19} = \frac{19 \cdot 49}{56 \cdot 19} = \frac{19 \cdot 7 \cdot 7}{7 \cdot 8 \cdot 19} = \frac{7}{8}$$.
Ответ: $$\frac{7}{8}$$
e) $$1\frac{3}{4} \cdot 36 = \frac{1 \cdot 4 + 3}{4} \cdot \frac{36}{1} = \frac{7}{4} \cdot \frac{36}{1} = \frac{7 \cdot 36}{4 \cdot 1} = \frac{7 \cdot 4 \cdot 9}{4} = 7 \cdot 9 = 63$$.
Ответ: $$63$$
и) $$5\frac{7}{7} \cdot \frac{1}{27} = 6 \cdot \frac{1}{27} = \frac{6}{27} = \frac{3 \cdot 2}{3 \cdot 9} = \frac{2}{9}$$.
Ответ: $$\frac{2}{9}$$