Question

calcule a soma dos 15 primeiros termos da PG ( 32, 16, 8...)

Answer 1

P.G(32,16,8,....
a 1 = 32
a 2 = 16
q = a 2/  a 1

q =   16/32
q = 1/2

S 15  = a 1 . (q^n  - 1 / q - 1
S 15  = 32 . (1/2)^15   -   1 / 1/2  - 1
S 15 = 32 . (1/2^15   - 1  ) / -1/2
S 15 = 32 . (1/32768  - 1 ) / -1/2
S 15  = 32 .(-32767) / -1/2
S 15 = -1 0480544 / -1/2
S 15 = - 1 048 544  .  -2/1  
s 15 = 2 097 088