Answer:
The difference is 48 meters
Step-by-step explanation:
<u><em>The question is</em></u>
What is the difference of the hikers' altitudes?
Let
x -----> the Melissa's altitude in meters
y ----> Brian's altitude in meters
we have that
---> is positive because is above sea level
---> is negative because is below sea level
Remember that the sea level is the altitude equal to zero
<em>Find the difference</em>
To find out the difference of the hikers' altitudes, subtract Brian's altitude from Melissa's altitude
so

Remember that (-1)(-1)=+1
