I don't know how to do this. Can someone explain how to please?

Answer:
f(5) = -2
Step-by-step explanation:
You look on the x-axis for 5 because f(5) means let x = 5. Then go down to the graph (the red zig-zaggy line) At the red line (you're still directly under the 5) look over to the y-axis to find the value. That's your answer. It is -2. The point (5, -2) is on the red graph.
f(5) = -2