Circumference is the distance around the circle
You would be multiplying pi (3.14) by the number 5
ANSWER

EXPLANATION
From the table the values of x, are on the left and the values of f(x) are on the right.
To find f(-1), we look for the value under f(x) that corresponds to x=-1.
This value is 0.
Therefore

Or, is it asking you to subtract the? In that case
5/4 - 3/8 = 7/8