Real numbers question

Hi guys, I have NO idea what this means. What is it asking/stating? What does the star mean?
Thanks

By the term a* it means to subtract the value of a from 1.
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For example. 1* will be 1-(1)
2* will be 1-(2)

What they have given in the QA is
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Lets break it into steps. Opening the first item in the bracket.
We need to calculate (-1)*
which will be using the logic mentioned above as 1-(-1) which is 2
Now you need to calculate the star for the value you received i.e. (2)*

which is equal to quantity B

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Is this star notation something I should know? Have never seen it in newer questions.

No, it’s just an arbitrary notation used for this question alone.