Respuesta :

I believe to solve this question for the first term plug in n=1. For the fourth, n=4 and the 8th term, n=8 and solve these separate equations to obtain the value for each term.
a(1) = 5*3^0 = 5*1 = 5 

a(4) = 5*3^4 = 5*81 = 405

a(8) = 5*3^8 = 5*81*81 = 32805

hope this will help you