Find the value of f(x) when x = 0
f(0) =(0)²+4(0)-1

You did the correct thing and now you need to simplify the question. The answer would be -1. 0 squared is 0 and 4 times 0 is 0. That would leave you with -1.

Yea so you substitute the 0 into x so
F(0) = (0)^2 + 4(0) -1
F(0) = 0 + 0 -1
F(0) = -1