[Risolto] Espressioni algebriche

(1/a^2 + 1/b^2 - 1/(a·b))·(a^3·b^2/(a^3 + b^3))=

C.E. a ≠ 0 ∧ b ≠ 0 ∧ a ≠ -b

=(a^2 - a·b + b^2)/(a^2·b^2)·(a^3·b^2/((a + b)·(a^2 - a·b + b^2)))=

=a/(a + b)