Solve for n over the real numbers:
660 (1.25^(n+1)-4.)-660 = 0
660 (1.25^(n+1)-4.)-660 = 660 ((5/4)^(n+1)-4)-660:
660 ((5/4)^(n+1)-4)-660 = 0
Factor constant terms from the left hand side:
825 ((5/4)^n-4) = 0
Divide both sides by 825:
(5/4)^n-4 = 0
Add 4 to both sides:
(5/4)^n = 4
Take the logarithm base 5/4 of both sides:
Answer: |n = (log(4))/(log(5/4))=6.212567.........etc.
