1) Вычислите: в) \(7\frac{7}{15} + 2\frac{9}{20}\)

в) \(7\frac{7}{15} + 2\frac{9}{20} = 7 + \frac{7}{15} + 2 + \frac{9}{20} = 9 + \frac{7 \cdot 4}{15 \cdot 4} + \frac{9 \cdot 3}{20 \cdot 3} = 9 + \frac{28}{60} + \frac{27}{60} = 9 + \frac{28+27}{60} = 9 + \frac{55}{60} = 9 + \frac{11}{12} = 9\frac{11}{12}\)