Answer:
For the first three situations, the sum is zero.
Step-by-step explanation:
As the expenses are negative of earnings, so assuming the earning amount is positive while the spending amount is negative.
Shawna spends $20 and she earns $20,
So, the sum of the total amount is
-20+20=0
A diver dove down 20.14 feet under-water and then descended 20.14 feet.
First, the diver ascends 20.14 feet then descends the same.
As the ascending and the descending are opposite to each other.
The sum of both is
+20.14-20.14=0
So, in this case, the diver has a sum of zero.
For shooting over par the golfer have +2 points while for shooting under par the golfer have -2 points,
So, the total points are
+2-2=0
So, in this case, the golfer has a sum of zero points.
In the last case, you already have $5.50 in your pocket and then you receive $5.50 for doing your chore.
This time, there is an addition of $5.50 to the money you already have.
So, the total money, after receiving the $5.50 is
$5.50+$5.50=$11
In this case, the sum of the total amount is not zero.
Hence, for the first three situations, the sum is zero.