SOLUTION
Given the graph in the image, the following are the solution steps to get the intervals where the graph is decreasing
Step 1: Define the decreasing interval of a graph
The graph of a function y = f(x) in an interval is decreasing (or falling) if all of its tangents have negative slopes. That is, it is decreasing if as x increases, y decreases.
Step 2: Pick the intervals where the graph is decreasing
It can be seen from the graph
