2.494 Вычислите: 1) 1\frac{1}{4}:2\frac{1}{1}:1\frac{2}{7}; 2) 4\frac{1}{3}:1\frac{7}{8}:\frac{13}{15}; 3) 1\frac{3}{7}:\frac{11}{15}:4\frac{5}{7}; 4) 1\frac{6}{7}:3\frac{5}{7}:\frac{4}{9}

1)

$$1\frac{1}{4}:2\frac{1}{1}:1\frac{2}{7} = \frac{5}{4}:\frac{3}{1}:\frac{9}{7} = \frac{5}{4} \cdot \frac{1}{3} \cdot \frac{7}{9} = \frac{5 \cdot 1 \cdot 7}{4 \cdot 3 \cdot 9} = \frac{35}{108}$$

2)

$$4\frac{1}{3}:1\frac{7}{8}:\frac{13}{15} = \frac{13}{3}:\frac{15}{8}:\frac{13}{15} = \frac{13}{3} \cdot \frac{8}{15} \cdot \frac{15}{13} = \frac{1 \cdot 8 \cdot 1}{3 \cdot 1 \cdot 1} = \frac{8}{3} = 2\frac{2}{3}$$

3)

$$1\frac{3}{7}:\frac{11}{15}:4\frac{5}{7} = \frac{10}{7}:\frac{11}{15}:\frac{33}{7} = \frac{10}{7} \cdot \frac{15}{11} \cdot \frac{7}{33} = \frac{10 \cdot 15 \cdot 1}{1 \cdot 11 \cdot 33} = \frac{150}{363} = \frac{50}{121}$$

4)

$$1\frac{6}{7}:3\frac{5}{7}:\frac{4}{9} = \frac{13}{7}:\frac{26}{7}:\frac{4}{9} = \frac{13}{7} \cdot \frac{7}{26} \cdot \frac{9}{4} = \frac{1 \cdot 1 \cdot 9}{1 \cdot 2 \cdot 4} = \frac{9}{8} = 1\frac{1}{8}$$

Ответ: 1) $$\frac{35}{108}$$, 2) $$2\frac{2}{3}$$, 3) $$\frac{50}{121}$$, 4) $$1\frac{1}{8}$$