Answer:
12
Explanation:
I am assuming you are asking for f(x)=x^2-3x+8? You plug (-1) in for all portions of x. This means you get (-1)^2-3(-1)+8. (-1)^2 is simply 1 because -1 x -1=1. 3*-1 is -3. This makes the equation 1 - (-3) + 8. The middle section simplifies down to +3 making it 1+3+8, or 12.