Question

determine a soma dos termos da pg 5/2 5/4 5/8

Answer 1

a1 = 5/2
a2 = 5/4
q = 5/4 : 5/2 = 5/4 * 2/5 = 10/20 =1/2 ****
S3 = 5/2 [ (1/2)³  - 1]/ ( 1/2 - 1/1)
S3 = 5/2 [ (1/8) - 1/1] / ( -1/2)
S3 = 5/2 ( -7/8) / ( - 1/2)
s3 = 5/2 ( -7/8  * - 2/1)
S3 = 5/2 ( 14/8 )
S3 = 5/2 * 14/8 = 70/16  = 35/8 ***