Answer: [tex]Marcu's\ elevation=-35\ ft[/tex]
Step-by-step explanation:
By definition, integers numbers can be positive, negative or zero.
Opposite integers are defined as those integers that have the same distance from zero but they are on opposite sides of the number line. Then one of them is positive and the other one is negative.
Knowing this you can solve the problem.
Let be [tex]0[/tex] the sea level.
You know that the Kim's is on a hillside and her elevation is 35 feet above sea level. Then:
[tex]Kim's\ elevation=35\ ft[/tex]
Since Marcus's elevation is opposite of Kim's elevation, this means that the his elevation is:
[tex]Marcu's\ elevation=-35\ ft[/tex]