Respostas

2014-08-14T09:51:41-03:00
X + ( 3 + r) + (x + 2r) + (5 + 3r) + ( x + 4r ) + ( x + 5r ) + ( x + 6r) + ( x + 7r )
+ ( x + 7r) + ( x + 8r ) + ( x + 9r)
 
 Os "x" representam os termos e os "r" a razão somada a cada termo