Question

Dado a+b=5 e ab = 3, então o valor de a³ + b³ é?

Answer 1

(a+b)*2= 5*2
a*2+2.ab+ b*2= 25
a*2+ 2.3+ b*2= 25
6(a*2+b*2)= 25
(a*2 + b*2) = 25+ 6
= 31