Science and medicine. A bicyclist rode into the country for 5 h. In returning, her

speed was 5 mi/h faster and the trip took 4 h. What was her speed each way?
x for 5h
x+ 5 miles for 4 hours
5x = 4 (x+ 5)
5x = 4x + 20
20 miles there
20 miles back
-x = -20

You should use better English for you defining statement.
e.g.
Let her speed going into the country be x mph, let her speed on the return trip be (x+5) mph

In your solution you should have one more line
x=20, (why do you even have that -20=-x ???)

and finish the whole thing off with a proper English sentence conclusion.