The user provided an image containing mathematical expressions and wants them to be transcribed and potentially solved.

Задание 2

а) \( 2\frac{2}{3} : \frac{7}{9} + \frac{55}{84} : \left( \frac{43}{36} - \frac{23}{63} \right) \)

б) \( \frac{2.1 \cdot \frac{1}{3} - 1.4 \cdot \frac{1}{11}}{0.7 \cdot \frac{1}{11}} \)