Question

Помогите пожалуйста!!!

Answer 1

$frac{a}{a-b} + frac{a^{2}+b^{2}}{b^{2}-a^{2}} + frac{a}{a+b} = frac{a(a+b)}{(a-b)(a+b)} - frac{a^{2}+b^{2}}{a^{2}-b^{2}} + frac{a(a-b)}{(a-b)(a+b)} = \ = frac{a^{2}+ab-a^{2}-b^{2}+a^{2}-ab}{a^{2}-b^{2}}= frac{a^{2}-b^{2}}{a^{2}-b^{2}} =1$