Question

Calcule a soma dos 10 primeiros termos da p.g.(3, 6 , 12,...).

Answer 1

SN=[a1(q*n-1)]/q-1
q=a2/a1=6/3=2
sn=3(2*10-1)/2-1
SN=6×2*9/1
sn=6×512
sn=3072

Answer 2

a1 = 3
a2 = 6
q =  6/3 = 2 ***

n = 10
a10 = a1q^9 =  3 *2^9 =   3 * 512 = 1536

S10 =  3 ( 2^10  - 1 )/ ( 2 - 1)
S10 = 3 ( 1024 - 1)
S10  = 3 * 1023 = 3069 ****