Решите пожалуйста Б и Г очень прошу !!!!!!!!

Б)
$( \frac{c+3}{c-3}- \frac{c}{c+3} )* \frac{c-3}{c+1}= \frac{(c+3)^2-c(c-3)}{(c-3)(c+3)}* \frac{c-3}{c+1}= \\ \\ = \frac{c^2+6c+9-c^2+3c}{c+3}* \frac{1}{c+1}= \frac{9c+9}{c+3}* \frac{1}{c+1}= \\ \\ = \frac{9(c+1)}{c+3}* \frac{1}{c+1}= \frac{9}{c+3}$

г)
$(\frac{a}{a-4}- \frac{a-4}{a+4} )* \frac{a+4}{4}= \frac{a(a+4)-(a-4)^2}{(a-4)(a+4)}* \frac{a+4}{4}= \\ \\ = \frac{a^2+4a-a^2+8a-16}{a-4}* \frac{1}{4}= \frac{12a-16}{a-4}* \frac{1}{4}= \\ \\ = \frac{4(3a-4)}{a-4} * \frac{1}{4}= \frac{3a-4}{a-4}$