Respuesta :

Answer:

418 4/10

Step-by-step explanation:

To answer this we subtract 450 7/10 from 869 1/10.

We must borrow a '1' from 869 1/10:  868 11/10

Now subtract 450 7/10 from 868 11/10:

418 4/10 (CHANGE IN ELEVATION)

This reduces to 418 2/5.