Задание 80: Найдите значение выражения.

1) \( \frac{2}{4} + \frac{3}{8} - \frac{1}{2} = \frac{1}{2} + \frac{3}{8} - \frac{4}{8} = \frac{1}{8} \). 2) \( \frac{2}{4} + \frac{3}{8} : \frac{1}{2} = \frac{1}{2} + \frac{3}{8} \times 2 = \frac{1}{2} + \frac{6}{8} = \frac{1}{2} + \frac{3}{4} = \frac{5}{4} \). 3) \( \frac{6}{4} - \frac{5}{1} : \frac{1}{9} \times \frac{32}{1} = \frac{6}{4} - \frac{45}{9} \times \frac{32}{1} = \frac{3}{2} - 160 = -158 \frac{1}{2} \). 4) \( \frac{3}{4} + \frac{2}{1} : \frac{6}{2} + \frac{2}{3} : \frac{4}{9} = \frac{3}{4} + \frac{2}{1} \times \frac{2}{6} + \frac{2}{3} \times \frac{9}{4} = \frac{3}{4} + \frac{4}{6} + \frac{18}{12} = \frac{3}{4} + \frac{2}{3} + \frac{3}{2} = \frac{1}{4} + \frac{1}{2} + \frac{3}{2} = \frac{7}{4} \).