For #1 you're just plugging in the numbers that are in the parentheses for x.
For example:
f(2)
Take the given equation to plug in for x:
x^2-4x+5
(2)^2-4(2)+5
And from there you get the answer. Your final answer will look like this:
f(2)=? {the answer you got when you plugged in}
