That first one you have selected (3,-3) works in both equations so it's correct.
good job.
you can do this guess and test method with multiple choice answers. If it works in both equations it is the solution. Otherwise use substitution or elimination to combine the two into one equation in only one variable. Then you can solve for the one variable first and use it to solve for the other.
Answer:
h=15.27m
Explanation:
Since at maximum height the vertical velocity must be null it's better to use the formula:

We will use this formula for the vertical direction, choosing the upward direction as the positive one, so we have:

or

which for our values is:

football hemets have pads that are filled with air and thick foam so when they are hit the foam asorbs the hit and the air keeps the hard outer shell of the helmet from hiting the players head