Question

$\frac{1+\sqrt{7}}{1-\sqrt{7}}+\frac{1-\sqrt{7}}{1+\sqrt{7}}$

Answer 1

$\frac{1+\sqrt{7}}{1-\sqrt{7}}+\frac{1-\sqrt{7}}{1+\sqrt{7}}\frac{(1+\sqrt{7}{)}^2+(1-\sqrt{7}{)}^2}{1-7}\frac{1+7+2\sqrt{7}+1+7-2\sqrt{7}}{-6}\frac{16}{-6}=-\frac{8}{3}$