ПОМОГИТЕ ПОЖАЛУЙСТА!!!!!!!!!!!!!!!!!!!!

Решите задачу:

$\frac{63a^3b}{c}:(18a^2b)= \frac{63a^3b}{c}*\frac{1}{18a^2b} = \frac{7a}{2c} \\\\\\ \frac{4a^2-1}{a^2-9}: \frac{6a+3}{a+3}= \frac{(2a-1)(2a+1)}{(a-3)(a+3)}* \frac{a+3}{3(2a+1)}= \frac{2a-1}{3(a-3)}= \frac{2a-1}{3a-9} \\\\\\ \frac{p-g}{p}*( \frac{p}{p-g}+ \frac{p}{g} )= \frac{p-g}{p}* \frac{p}{p-g}+\frac{p-g}{p}* \frac{p}{g} =1+ \frac{p-g}{g}= \frac{g+p-g}{g}= \frac{p}{g}$