Draw a diagram to illustrate the problem as shown below.
Let v = speed of the westbound car, mph
Because the eastbound car travels 4 mph faster than the westbound car, its speed is (v+4) mph.
After 2 hours,
the westbound car travels 2v miles west, and the eastbound car travels 2(v+4) miles east.
Because they become separated by 208 miles, therefore
2v + 2(v+4) = 208
4v + 8 = 208
4v = 200
v = 50 mph
The westbound car travels at 50 mph.
The eastbound car travels at v+4 = 54 mph
Answer: The eastbound car travels at 54 mph.
Let v = speed of the westbound car, mph
Because the eastbound car travels 4 mph faster than the westbound car, its speed is (v+4) mph.
After 2 hours,
the westbound car travels 2v miles west, and the eastbound car travels 2(v+4) miles east.
Because they become separated by 208 miles, therefore
2v + 2(v+4) = 208
4v + 8 = 208
4v = 200
v = 50 mph
The westbound car travels at 50 mph.
The eastbound car travels at v+4 = 54 mph
Answer: The eastbound car travels at 54 mph.