Question

a/b+b/a=-1 then(a×a×a-b×b×b)=?

Answer 1

a/b + b/a = -1

=> (a^2 + b^2)/ab = -1

=> a^2 + b^2 = -ab

=> a^2 + b^2 + ab = 0   -----------1

so, a^3 - b^3 = (a - b) (a^2 + b^2 + ab)   (by using 1)

                    = (a - b) * 0 = 0   Ans....