a) $$8/15 \cdot 2 = 16/15 = 1 \frac{1}{15}$$
Ответ: $$1 \frac{1}{15}$$
б) $$3 \frac{9}{14} \cdot 7 = \frac{3 \cdot 14 + 9}{14} \cdot 7 = \frac{42+9}{14} \cdot 7 = \frac{51}{14} \cdot 7 = \frac{51}{2} = 25 \frac{1}{2}$$
Ответ: $$25 \frac{1}{2}$$
в) $$7 \frac{4}{27} \cdot 5 = \frac{7 \cdot 27 + 4}{27} \cdot 5 = \frac{189+4}{27} \cdot 5 = \frac{193}{27} \cdot 5 = \frac{965}{27} = 35 \frac{20}{27}$$
Ответ: $$35 \frac{20}{27}$$
г) $$8 \cdot 2 \frac{1}{8} = 8 \cdot \frac{2 \cdot 8 + 1}{8} = 8 \cdot \frac{16+1}{8} = 8 \cdot \frac{17}{8} = 17$$
Ответ: 17
д) $$5 \frac{5}{6} \cdot 3 = \frac{5 \cdot 6 + 5}{6} \cdot 3 = \frac{30+5}{6} \cdot 3 = \frac{35}{6} \cdot 3 = \frac{35}{2} = 17 \frac{1}{2}$$
Ответ: $$17 \frac{1}{2}$$
е) $$7 \frac{7}{11} \cdot 11 = \frac{7 \cdot 11 + 7}{11} \cdot 11 = \frac{77+7}{11} \cdot 11 = \frac{84}{11} \cdot 11 = 84$$
Ответ: 84