Answer:
x = -1
Explanations:
Note:
f(x) is the vertical axis of the graph
x is the horizontal axis of the graph
To get the value of x when f(x) = 4:
Locate the point on the graph that is on the "4" on the vertical axis and trace it downwards to get the value of x.
If that is done, we would observe that x = -1 when f(x) = 4