1. Выполните сложение: (a) \( \frac{3}{5} + \frac{7}{40} \) = \( \frac{32}{40} + \frac{7}{40} = \frac{39}{40} \). (b) \( \frac{5}{7} + \frac{12}{9} \) = \( \frac{45}{63} + \frac{84}{63} = \frac{129}{63} = 2\frac{3}{63} \). (c) \( \frac{9}{14} + \frac{35}{35} \) = \( \frac{45}{70} + \frac{70}{70} = \frac{115}{70} = 1\frac{45}{70} \).