Question

20° termo da PA (2,8.......)

Answer 1

An = a1 + (n-1) × r
a20 = 2 + (20 - 1) × 6
a20 = 2 + 19×6
a20 = 2 + 114
a20 = 116

Answer 2

a20 = 2 + 19.6 ==> a20 = 2 + 114 ==> a20 = 116

S20 = (2+116).20 ==> 118.5 ==> 590
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