Question

The sequence x_1, x_2, x_3, . . ., has the property that x_n = x_{n - 1} + x_{n - 2} for all n \ge 3. If x_{11} - x_1 = 99, then determine x_6.
Steve, you made a mistake for x_4.

Answer 1

well, did you fix it? Not sure what you mean, since I had x11-x1 = 99 and the sequence

3,0,3,3,6,9,15,24,39,63,102

has Xn = X(n-1)+X(n-2) for n>2

Answer 2

everything got confusing after that

Answer 3

You might want to study up on the Fibonacci series. That's what the Fn values were.