Question

2 la puterea 2 + 2 la puterea 4 + 2 la puterea 6 +..........+2 la puterea 50 =

Answer 1

= progresie geometrica cu ratia q=2^2=4 si 50-2  :  2 +1 = 25 termeni ⇒
S=2^2 [(2^2)^25  -  1] : (2^2 - 1) = 4/3 * (2^50 - 1) si asa ramane.