please show work and answer this problem

4. One ship, Ship A, is approaching a port from the east, traveling west at 15 miles per hour, and is presently 3 miles east of the port. A second ship, ship B, has already left the port, traveling to the north at 10 miles per hour, and is presently 4 miles north of the port. At this instant, what is the rate of change of the distance between the two ships? Are they getting closer or further apart? [3 pts]