From the graphs of f and g in the figure, we find the following. (Assume that each point lies on the grid lines)

Question

(f+g)(8)= ?

(f-g)(8)=?

(fg)(8)=?

(f/g)(8)=?

Answer 1

I cannot see your graph. Go over to 8 on the x-axis. Go separately to the y-coordinate for f and the y-coordinate for g. say that the y-coordinate for f is y=f(8)= -3 and that the y-coordinate for g is y=g(8)= 17. then

(f+g)(8) = f(8)+g(8) = -3+17=14 and (f-g)(8)=f(8)-g(8) = -3-17= -20

(fg)(8)= f(8)*g(8)=3 * (-17) = -51 ..always nice to have () when multiplying negatives

(f/g)(8) = f(8)/g(8) = -3/17