Respuesta :

[tex]a_1=1;\ r=3\\\\a_n=a_1r^{n-1}\to a_n=1\cdot3^{n-1}=3^{n-1}\\\\a_7=3^{7-1}=3^6=729\\\\Answer:\boxed{a_7=729}[/tex]
The seventh term of a sequence whose first term is 1 and whose common ratio is 3 is 729.