Replace x with -24. Replace y with 6. Then use PEMDAS to simplify
So we have x+y = -24+6 = -18
If the negatives throw you off, then think of it like this: you are 24 dollars in debt so that is represented by -24. If you pay $6 back, then you are 18 dollars in debt (24-6 = 18)
Or you can use a number line. Start at -24 on the number line. Then move 6 spots to the right to land on -18
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Since we have vertical bars surrounding x+y, this means that the result will be positive. Remember that absolute value represents distance. Negative distance makes no sense.
So |x+y| = |-18| = 18
Final Answer is 18