Determine all prime numbers so that and equal the same prime number.
Solution
Let be the prime numbers that satisfy the conditions of the problem. If then all are odd thus the number is even and the number is odd, which contradicts the conditions of the problem. Therefore, , thus:
, that means and . Therefore, . After solving the last inequality, we will have that . Prime numbers that satisfy this inequality are and .
If , then is not prime.
If , then is prime, that implies , and , that means .
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