Respuesta :

Given:

Geometric sequence is:

1,-4,16,-64

Sol:

For geometric sequence is:

[tex]a_n=a_1r^{n-1}[/tex][tex]\begin{gathered} a_1=1 \\ a_2=-4 \end{gathered}[/tex][tex]\begin{gathered} a_n=a_1r^{n-1} \\ -4=1r^{2-1} \\ -4=r \end{gathered}[/tex]

Common ratio is -4.