Respuesta :

f4 can be rewritten to:

f(4) = f(3+1) = -2f(3)    [Using f(n+1) = -2f(n)]

Keep using f(n+1):

-2f(3) = -2f(2+1) = -2[-2f(2)] = 4f(2)

Again:

4f(2) = 4f(1+1) = 4[-2f(1)] = -8f(1) = -8*160

-8*160 = -1280

Answer:

-1,280

Step-by-step explanation: