SOLUTION:
We are given two functions;
f(x) which is an absolute value equation and g(x) which is a graph.
We have to give the interval over which both functions are decreasing.
From the graph of g(x), we see that g(x) decreases over the interval;

and plotting the diagram of f(x), we have;
We see that f(x) decreases on the interval;

Thus, the interval over which both funtions decrease which is the intersection of both functions is;

Representing this on a number line, we have;