Заполни таблицу и реши примеры.

a	$$\frac{7}{13}$$	$$\frac{8}{21}$$	$$\frac{19}{53}$$
b	$$\frac{4}{13}$$	$$\frac{5}{17}$$	$$\frac{19}{28}$$
a + b	$$\frac{11}{13}$$	$$\frac{12}{17}$$	$$\frac{32}{53}$$
a - b	$$\frac{3}{13}$$	$$\frac{2}{21}$$	$$\frac{9}{28}$$

Решение примеров:

1)

Начинаем с $$\frac{5}{23}$$ и прибавляем $$\frac{9}{23}$$:

$$\frac{5}{23} + \frac{9}{23} = \frac{5+9}{23} = \frac{14}{23}$$

Затем вычитаем $$\frac{7}{23}$$:

$$\frac{14}{23} - \frac{7}{23} = \frac{14-7}{23} = \frac{7}{23}$$

Прибавляем $$\frac{16}{23}$$:

$$\frac{7}{23} + \frac{16}{23} = \frac{7+16}{23} = \frac{23}{23} = 1$$

Вычитаем $$\frac{18}{23}$$:

$$1 - \frac{18}{23} = \frac{23}{23} - \frac{18}{23} = \frac{23-18}{23} = \frac{5}{23}$$

2)

Начинаем с $$\frac{23}{59}$$ и прибавляем $$\frac{7}{59}$$:

$$\frac{23}{59} + \frac{7}{59} = \frac{23+7}{59} = \frac{30}{59}$$

Затем вычитаем $$\frac{11}{59}$$:

$$\frac{30}{59} - \frac{11}{59} = \frac{30-11}{59} = \frac{19}{59}$$

Прибавляем $$\frac{15}{59}$$:

$$\frac{19}{59} + \frac{15}{59} = \frac{19+15}{59} = \frac{34}{59}$$

Прибавляем $$\frac{17}{59}$$:

$$\frac{34}{59} + \frac{17}{59} = \frac{34+17}{59} = \frac{51}{59}$$