Write an equation for the nth term of the geometric sequence 5,20,80,320 ...

5,20,80,320

Your input appears to be an geometric series.

Find the ratio (r) between adjacent members a2/a1=20/5=4 a3/a2=80/20=4 a4/a3=320/80=4

The ration (r) between every two adjacent members of the series is constant and equal to 4

General Form: an=a1*rn-1 This geometric series: an=5*4 n-1