7 Найди значение выражения х + \frac{15}{42}, если х = \frac{4}{42}, \frac{8}{42}, \frac{25}{42}

Решение:

1) x = \frac{4}{42}

$$x + \frac{15}{42} = \frac{4}{42} + \frac{15}{42} = \frac{4 + 15}{42} = \frac{19}{42}$$

2) x = \frac{8}{42}

$$x + \frac{15}{42} = \frac{8}{42} + \frac{15}{42} = \frac{8 + 15}{42} = \frac{23}{42}$$

3) x = \frac{25}{42}

$$x + \frac{15}{42} = \frac{25}{42} + \frac{15}{42} = \frac{25 + 15}{42} = \frac{40}{42} = \frac{20}{21}$$

Ответ: \frac{19}{42}, \frac{23}{42}, \frac{20}{21}