The given image represents a function
If you plot the given inputs and outputs on a graph, it's easier to see whether the given relation is a function.
The Vertical Line Test allows us to know whether or not a graph is actually a function. If a vertical line intersects the graph in all places at exactly one point, then the relation is a function.
Plotting the points of the given relation on a graph shows that there is only 1 point for each of the vertical lines (in purple) drawn on the graph. This means that the given relation passed the vertical line test, indicative of a function.
i graphed to on desmos.