The entire expression should be subtracted from 30. To subtract the quantity, distribute the negative sign, which changes the signs on the terms. So, the –2 changes to positive and gets added to 30 instead of subtracted from it.
Submarine: -730 Airplane: 9,144 |-730-9,144|=|-9,874|=9,874 |d|: absolute value The vertical distance between the submarine and airplane is 9,874 meters.
