Question

а²-b² a³-b³
------- - --------- =
a-b a²-b²

Answer 1

1) (а^2 - b^2) / ( а - b) = a + b
2) (a^3 - b^3)/ ( a+b)× (a-b ) =(a^2 + ab + b^2) / ( a+b)
3) (( a + b)^2 - ( a^2 + ab + b^2)) / ( a+ b) = 3ab / ( a+b)