Answer:
1,171 miles
Explanation:
The trip is 1792 miles.
They have driven (58857 - 58236) miles of the trip so far (because the odometer change is equal to the distance driven).
(58857 - 58236) = 621
They still need to drive 1792 - 621 miles
1792 - 621 = 1171
So they have 1171 miles left until they complete the trip.