Answer :
The downward distance they travel is -1500x
How to indicate the downward distance they travel
From the question, we have the following parameters that can be used in our computation:
Distance each day = 1500 meters
Represent the number of days with x
So, we have
Total distance = -1500 * x
Evaluate
Total distance = -1500x
hence, the downward distance they travel is -1500x
