Answer: 163 dollars
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Explanation:
Let's add up the positive values only for now. So we get 172+48 = 220 which represents all the money coming into the account.
Do the same for the negative values. We'll simply add the positive versions of each (ignore the negative signs). So -17 and -40 can be thought of as 17 and 40, which add to 17+40 = 57. Ultimately this result is negative leading us to -57.
In other words, -17 + (-40) = -57
So you can see that adding negatives follows the same rule as positives. The only change is that everything turns negative.
The notation -57 means that 57 dollars is going out in terms of expenses, purchases, withdrawals, fees, etc.
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To summarize everything so far:
- 220 dollars in total is coming in
- 57 dollars in total is going out
We subtract those results to find the final balance
balance = moneyIn - moneyOut = 220-57 = 163 dollars
We subtract positive versions of each number.
