Вычисли дроби: a) 5/14 + 5/21

a) \(\frac{5}{14} + \frac{5}{21}\) = \(\frac{5 \cdot 3}{14 \cdot 3} + \frac{5 \cdot 2}{21 \cdot 2}\) = \(\frac{15}{42} + \frac{10}{42}\) = \(\frac{25}{42}\) б) \(\frac{5}{14} - \frac{5}{21}\) = \(\frac{5 \cdot 3}{14 \cdot 3} - \frac{5 \cdot 2}{21 \cdot 2}\) = \(\frac{15}{42} - \frac{10}{42}\) = \(\frac{5}{42}\) в) \(\frac{17}{30} + \frac{11}{70}\) = \(\frac{17 \cdot 7}{30 \cdot 7} + \frac{11 \cdot 3}{70 \cdot 3}\) = \(\frac{119}{210} + \frac{33}{210}\) = \(\frac{152}{210}\) = \(\frac{76}{105}\) г) \(\frac{17}{30} - \frac{11}{70}\) = \(\frac{17 \cdot 7}{30 \cdot 7} - \frac{11 \cdot 3}{70 \cdot 3}\) = \(\frac{119}{210} - \frac{33}{210}\) = \(\frac{86}{210}\) = \(\frac{43}{105}\) д) \(\frac{9}{22} + \frac{2}{121}\) = \(\frac{9 \cdot 11}{22 \cdot 11} + \frac{2 \cdot 2}{121 \cdot 2}\) = \(\frac{99}{242} + \frac{4}{242}\) = \(\frac{103}{242}\) e) \(\frac{9}{22} - \frac{2}{121}\) = \(\frac{9 \cdot 11}{22 \cdot 11} - \frac{2}{121}\) = \(\frac{99}{242} - \frac{4}{242}\) = \(\frac{95}{242}\)