Question

Determine a soma dos 20 primeiros termos da PA (10,18,26,...)

Answer 1

r=8
a₂₀=a₁+(20-1)r
a₂₀= 10+19.8
a₂₀=162

S₂₀=(10+162)20/2
S₂₀= 172.10= 1720

Answer 2

Olá!

(10,18,26...34,42,50,58,66,74,82,90,98,106,114,122,130,138,146,154,162,170,178 e 186.)

Espero ter ajudado: 3