Question

已知a+b=5,ab=3,求分式a²;+b²/a³;+b³等于多少?

Answer 1

(a^2+b^2)/(a^3+b^3)

=[(a+b)^2-2ab]/(a+b)[(a+b)^2-3ab]

=(25-6)/5*(25-9)

=19/80