Question

.........Номер 4............

Answer 1

$frac{10}{(5-b^2)(5+b^2)}+ frac{1}{5+b^2}- frac{1}{5-b^2}= frac{10+5-b^2-5-b^2}{(5-b^2)(5+b^2)}=frac{10-2b^2}{(5-b^2)(5+b^2)}=frac{2(5-b^2)}{(5-b^2)(5+b^2)} \ = frac{2}{5+b^2}$