Найти производную функции

Решите задачу:

$y = \bigg ( \cfrac{x-2}{x+6} \bigg )^{ \dfrac{5}{7}} \\ \\ v = \cfrac{x-2}{x+6} ; \ u = v^{{ \dfrac{5}{7}}} \\ \\ \\ y' = v' \cdot u' = \dfrac{(x - 2)'(x + 6) - (x + 6)'(x - 2)}{(x + 6)^2} \cdot \dfrac{5}{7} v^{{ -\dfrac{2}{7}}} = \\ \\ \dfrac{5}{7} \cdot \dfrac{x + 6 - x + 2}{(x + 6)^2} \cdot \bigg ( \cfrac{x-2}{x+6} \bigg )^{{ -\dfrac{2}{7}}} = \dfrac{40 \sqrt[7]{(x + 6)^2}}{7(x + 6)^2 \cdot \sqrt[7]{ (x - 2)^2}} = \\ \\ \dfrac{40 }{ 7\sqrt[7]{(x - 2)^2} \cdot \sqrt[7]{ (x + 6)^{12}}}$