Respuesta :

bcalle
(2/3)^(1-1) + (2/3)^(2-1) + (2/3)^(3-1) + (2/3)^(4-1)=
(2/3)^0 + (2/3)^1 + (2/3)^2 + (2/3)^3= 
1 + (2/3) + (4/9) + (8/27) = 
(27/27) + (18/27) + (12/27) + (8/27) =
65/27 = 2 11/27