1. Вычислите: 1) \(\frac{12}{35}\) : \(\frac{2}{5}\); 2) \(\frac{15}{17}\) :5; 3) 4: \(\frac{20}{21}\); 4) 8\(\frac{3}{4}\) :2\(\frac{1}{3}\).

1) \(\frac{12}{35}\) : \(\frac{2}{5}\) = \(\frac{12}{35}\) × \(\frac{5}{2}\) = \(\frac{12×5}{35×2}\) = \(\frac{6×1}{7×1}\) = \(\frac{6}{7}\)

2) \(\frac{15}{17}\) :5 = \(\frac{15}{17}\) : \(\frac{5}{1}\) = \(\frac{15}{17}\) × \(\frac{1}{5}\) = \(\frac{15×1}{17×5}\) = \(\frac{3×1}{17×1}\) = \(\frac{3}{17}\)

3) 4: \(\frac{20}{21}\) = \(\frac{4}{1}\) : \(\frac{20}{21}\) = \(\frac{4}{1}\) × \(\frac{21}{20}\) = \(\frac{4×21}{1×20}\) = \(\frac{1×21}{1×5}\) = \(\frac{21}{5}\) = 4\(\frac{1}{5}\)

4) 8\(\frac{3}{4}\) :2\(\frac{1}{3}\) = \(\frac{35}{4}\) : \(\frac{7}{3}\) = \(\frac{35}{4}\) × \(\frac{3}{7}\) = \(\frac{35×3}{4×7}\) = \(\frac{5×3}{4×1}\) = \(\frac{15}{4}\) = 3\(\frac{3}{4}\)

Ответ: 1) \(\frac{6}{7}\); 2) \(\frac{3}{17}\); 3) 4\(\frac{1}{5}\); 4) 3\(\frac{3}{4}\)