2. Выполните сложение: а) (-8) + 4; б) \(\frac{1}{7} + \frac{4}{9}\)

а) (-8) + 4 = -4 б) \(\frac{1}{7} + \frac{4}{9}\) = \(\frac{1*9}{7*9} + \frac{4*7}{9*7}\) = \(\frac{9}{63} + \frac{28}{63}\) = \(\frac{9+28}{63}\) = \(\frac{37}{63}\) Ответ: а) -4; б) \(\frac{37}{63}\)