okay so i know that this isnt directly VB related, but I have a HUGE problem with this equation:

These are terms of the fibonacci sequence:
F(n+2)= F(n+1) + Fn where n is greater than or equal to 1 and F1 = 1, F2= 1
If Fn is the nth Fibonacci number, verify that:
F9 * F7 - F8 ^2 = 1, By considering other terms in this form, (i.e. F4 * F2 - F3^2) determine a simplified expression for F(n+1) * F (n-1) - Fn^2.
Also, it has been discovered that if n is even and n^2 is odd, the result will be -1, while if n is odd and n^2 is even, the result will be 1

can anyone give me a simplified expression?!?