2 Выполните сложение: a) 3/10 + 4/10 ; б) 1/2 + 1/2; в) 3/7 + 5/7; г) 12/31 + 18/31 ; д) 2/3 + 3/3; e) 4/5 + 1/5 + 2/5.

• а) \(\frac{3}{10} + \frac{4}{10} = \frac{3+4}{10} = \frac{7}{10}\)
• б) \(\frac{1}{2} + \frac{1}{2} = \frac{1+1}{2} = \frac{2}{2} = 1\)
• в) \(\frac{3}{7} + \frac{5}{7} = \frac{3+5}{7} = \frac{8}{7}\)
• г) \(\frac{12}{31} + \frac{18}{31} = \frac{12+18}{31} = \frac{30}{31}\)
• д) \(\frac{2}{3} + \frac{3}{3} = \frac{2+3}{3} = \frac{5}{3}\)
• е) \(\frac{4}{5} + \frac{1}{5} + \frac{2}{5} = \frac{4+1+2}{5} = \frac{7}{5}\)

Ответ: а) \(\frac{7}{10}\), б) 1, в) \(\frac{8}{7}\), г) \(\frac{30}{31}\), д) \(\frac{5}{3}\), е) \(\frac{7}{5}\)