Question

DETERMINAR A SOMA DOS 30 PRIMEIROS TERMOS DA PA (2,5,...)

Answer 1

Ola, Evily! 

1°
an=a1+(n-1).r
an=2+(30-1).3
an=2+29.3
an=2+87
an=89

2°
sn30=(2+89).30/2
sn30=91.30/2
sn30=2730/2
sn30=1365