Question

Quantos termos tem a PA(5,10....625)?

Answer 1

An=a1+(n-1).r

An=5+624.5
 An=3125

Answer 2

Olá, Rhanuel. (=^.^=)/

(5,10,15,20,25,30,35,40,45,50,55,60,65,70,75,80,85,90,95,100,105,110,115,120,125,130,135,140,145,150,155,160,165,170,175,180,185,190,195,200,205,210,215,220,225,230,235,240,245,250,255,260,265,270,275,280,285,290,295,300,305,310,315,320,325,330,335,340,345,350,355,360,365,370,375,380,385,390,395,400,405,410,415,420,425,430,435,440,445,450,455,460,465,470,475,480,485,490,495,500,505,510,515,520,525,530,535,540,545,550,555,560,565,570,575,580,585,590,595,600,605,610,615,620,625)

An = 5
N = 205
An = A205 = 625
R = 5

A PA tem 205 termos. 

Espero ter ajudado.
Bons estudos! :-D