Answer:
Tthe distance between the police station and the fire station is 4 miles
Explanation:
Let's call x the distance between the library and the police station
Let's call z the distance between the police station and the fire station
We know that:
miles
The distance (x) between the library and the police station is 3 miles less than twice the distance (z) between the police station and the fire station
This is:

We wish to find the distance z.
Then we equate both equations and solve for the variable z
