Respostas

2013-04-23T18:59:07-03:00

a1= 20

a2=25

r= 25-20=5

an=5.005

 

 an= a1+ n-1.r

5.005= 20 +  n-1.5

5.005-20+5= 5n - 5

4990 = 5n

 

n=998 termos.

2 4 2