Question

a soma dos n primeiros termos da pa (6, 10, 14, ...) é 510. calcular n

Answer 1

N¹= 6
R=4
N= 510
An=?=

An= 5+(510-1)4
An= 5+509.4
An= 5+ 2036
An= 2040


Sn=(6+2040).510/2
Sn=2046.510/2
Sn=1,043,460/2
Sn=521,730