Determine whether the sequence is a geometric sequence. explain

Hello:

the sequence is a geometric sequence : An+1=q×An   q : is a common ratio
or : q=An+1/An
 ex01 :
the sequence    3 , 6 , 12 , 24 , 48 is a geometric sequence because:
48/24=24/12=12/6=6/3=2  ( common ratio : q)
ex02 : 
the sequence : An =5×3^n  is a geometric sequence because:
An+1= 5×3^(n+1)
         = 5×3^n ×3
         = 3×( 5×3^n)
       An+1  =3×An      ( common ratio : q = 3 )