for , this is a quadratic in and so has two roots, you need the positive one (which is what you have found).
The final answer is OK, but you give too many significant digits (only 5 are justified)Here's my work
which is in format.
Subbed my values in and I got t=2.1348 s
Plugged that value for t in the x equation and got 66.4194 ft. How does my equation look for finding t? If its right then I think I can assume my values for t and x are correct as well.