Сократите дробь: a) $$rac{a^2-ab+b^2}{a^3+b^3}$$; б) $$rac{a^3-b^3}{a-b}$$; в) $$rac{(a+b)^3}{a^3+b^3}$$.

a) $$rac{a^2-ab+b^2}{a^3+b^3} = rac{a^2-ab+b^2}{(a+b)(a^2-ab+b^2)} = rac{1}{a+b}$$

б) $$rac{a^3-b^3}{a-b} = rac{(a-b)(a^2+ab+b^2)}{a-b} = a^2+ab+b^2$$

в) $$rac{(a+b)^3}{a^3+b^3} = rac{(a+b)(a+b)(a+b)}{(a+b)(a^2-ab+b^2)} = rac{(a+b)^2}{a^2-ab+b^2} = rac{a^2+2ab+b^2}{a^2-ab+b^2}$$