I'm presuming that you have a table like this, and that you want to find the values of f(x)?
So, when x = -2, f(x) = 2 - 5(-2) = 2 + 5x2 = 2 + 10 = 12
when x = 1, f(x) = 2 - 5(1) = 2 - 5x1 = 2 - 5 = -3
You then repeat this process for each of the values of x that you've been given (i.e. x=-1, x=0, x=2), putting the value of x into the equation for f(x) to find the answer.