Решение

a) $$\frac{k^{6}}{7 - m} \cdot \frac{14 - 2m}{11k^{5}} = \frac{k^{6} \cdot 2(7 - m)}{(7 - m) \cdot 11k^{5}} = \frac{2k}{11}$$

б) $$-\frac{54k^{13}}{68g^{4}} : (-\frac{18k^{9}}{34g^{2}}) = \frac{54k^{13}}{68g^{4}} \cdot \frac{34g^{2}}{18k^{9}} = \frac{54 \cdot 34 \cdot k^{13} \cdot g^{2}}{68 \cdot 18 \cdot g^{4} \cdot k^{9}} = \frac{3 \cdot k^{4}}{2g^{2}} = \frac{3k^{4}}{2g^{2}}$$