Question

Calcule a soma dos 400 primeiros termos da p.a ( 4, 7, 10,...)

a) 241000
b) 60500
c) 135750
d) 2400
e) n.d.a

pufavor só responde quem souber... grato ​

Answer 1

Resposta:

Letra A

Explicação passo a passo:

r = 7 - 4  = 3

$a_4_0_0=a_1+399r\\\\a_4_0_0=4+399.3\\\\a_4_0=4+1197\\\\a_4_0_0=1201\\\\S_4_0_0=\frac{(4+1201)400}{2} \\\\S_4_0_0=1205.200\\\\S_4_0_0=241.000$