Answer:
21
Step-by-step explanation:
So, this is what is known as the Fibonacci Sequence. Basically, you add number to its preceding term. For example, 1 + 1 = 2 and so forth.
The equation for Fibonacci Sequences is x[tex]x_{n} = x_{n-1} + x_{n-2}[/tex]
Please let me know if you have any questions. Hope this helps!
Thanks,
Brady