Add & Subtract Fibonacci Numbers: Explained

[Bellarosa]

1. Can somebody please explain to me how you add Fibonacci numbers using the indices?


2. For example: f(2n+3) + f(2n)
I am actually trying to subtract f(2n) - f(2n+1) - 1
I really have difficulty understanding Fibonacci numbers.

 

[Bellarosa]

just a correction ...I am trying to subtract f(2n) -( [f(2n+1)] - 1)