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Question
If Y = {x | x is a positive factor of the number 2p – 1 (2p – 1), where 2p – 1 is a prime number}.Write Y in the roaster form.
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Solution
If 2p − 1 is a prime number, then its only positive factors are:
1 and 2p − 1
This is because prime numbers have exactly two positive factors: 1 and itself.
Let’s say p = 5, then:
25 − 1 = 32 − 1 = 31
31 is a prime number, so the factors of 31 are {1, 31}
Y = {1, 2p - 1}
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