Resposta:
q=1/6/-1/3
q=-3/6=-1/2
a1=-1/3
a12=a1.q¹¹
a12=-1/3.(-1/2)¹¹
a12= -1/3.(-1)¹¹/2¹¹
a12=-1/3.-1/2048
a12=1/6144
