Explanation:
once to understand how a function works, these are the most trivial questions to solve.
a function works that when you have a specific value for the input variable (here x), then you replace the name of the variable everywhere by that survival value. and then you simply calculate the result
p(-4) = 2×-4 - 5 = -8 - 5 = -13
that's it. there is nothing more to it.