Search within a range of matched IDs and find a matched pair of numbers

How do I return a result that says Match or No Match in column C after searching to see if an ID matches in column B and also the numbers in column A are opposite of each other?

Criteria:

1. Column B: ID must match
2. Numbers are opposite of each other in column A by searching in the range of the matched IDs in column B
3. Return the result in column C: "Match" or "No Match"

For example:

sample question.png

Solution.

Formula:

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I understand if True then return "Match" and if False then return "No match".

What I don't know is how the SUM function with the asterisk works. Do you mind explaining the logic behind the SUM function above?

Thank you so much for the formula.

Of course.

The formula returns to the function SUM a bunch of zeros and 1 (many cells..), the SUM function then return the sum of it all in 'one cell'.
"*" is the equivalent of function AND(), as "+" is the equivalent of the function OR().
So, the logic values TRUE and FALSE have an mathematical equivalent of 1 and 0, with them you can add and multiply.