Respuesta :

Answer:

[tex] a_1 = 5 [/tex]

[tex] a_n = 4a_{n - 1} [/tex]

Step-by-step explanation:

[tex] a_1 = 5 [/tex]

20/5 = 4

80/20 = 4

320/80 = 4

This a geometric sequence with r = 4.

[tex] a_n = 4a_{n - 1} [/tex]

Answer:

[tex] a_1 = 5 [/tex]

[tex] a_n = 4a_{n - 1} [/tex]