Can someone please answer this question please answer it correctly and please show work please help me I need it

Explanation:

Let's attach numbers to each variable

a = 1000

c = 700

If we start off at 1000 ft in the air, then go to 700 ft, then we moved 100 - 700 = 300 ft, which is the change in height.

Going from 700 back to 1000 ft is the same change in height, just the opposite direction. Note how 700 - 1000 = -300. Using absolute value will ensure the result is positive, so,  |700 - 1000| = | -300 | = 300.