Respostas

2014-04-03T17:02:37-03:00
2014-04-03T17:08:14-03:00
(2,4,6,8...)
a1=2
r=4-2=2
an=120
n=120-1
sn=?

an=a1+(n-1).r
a120=2+(120-1).2
a120=2+119.2
a120=240

sn=(2+240).120 /2
sn=242.120/2
sn=14520
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