Calculate
a) \(\frac{1}{7} + \frac{2}{3} \),  
b) \(\frac{1}{7} - \frac{2}{3} \),  
c) \(\frac{1}{7} \times \frac{2}{3} \),  
d) \(\frac{1}{7} / \frac{2}{3} \),  
e) \(\frac{3}{14} \left(\frac{2}{3} + 4 \right) \),  
f) \( \left( \frac{1}{9} + \frac{7}{3} \right) / \left(2 + \frac{26}{9} \right) \)