Answer:
521 feet.
Explanation:
In the given question, the number of feet covered with respect to climbing would have a positive value. While the number of feet descended would have negative value.
The total feet covered by Brody and Carrie, with the elevation of the trail-head should be equal to the elevation of their destination above sea level.
To determine the elevation of the trail-head, let its elevation be represented by h.
So that,
h + 103 - 84 + 194 = 734
h + 297 - 84 = 734
h + 213 = 734
h = 734 - 213
h = 521
h = 521 feet
The elevation of the tail-head is 521 feet.