2. Выполнить действия: A)+= Б) 1+2= B)-= Г)-

Решение:

A) \(\frac{5}{8} + \frac{3}{7} = \frac{5 \times 7 + 3 \times 8}{8 \times 7} = \frac{35 + 24}{56} = \frac{59}{56}\)

Б) \(1\frac{1}{5} + 2\frac{3}{10} = 1\frac{2}{10} + 2\frac{3}{10} = 3\frac{5}{10} = 3\frac{1}{2}\)

B) \(\frac{17}{20} - \frac{3}{4} = \frac{17 - 3 \times 5}{20} = \frac{17 - 15}{20} = \frac{2}{20} = \frac{1}{10}\)

Г) \(\frac{5}{6} - \frac{2}{9} = \frac{5 \times 3 - 2 \times 2}{18} = \frac{15 - 4}{18} = \frac{11}{18}\)