This question was uploaded on 19/01/22 on social media accounts.
Solution:
Given that x3 - 1 is a prime number and x is a natural number.
We know that, x3 - 1 = (x - 1)(x2 + x + 1)
If x3 - 1 is a prime number then it should not be a composite number,
for that either (x - 1) or (x2 + x + 1) should be 1.
If: x - 1 = 1 then x = 2, so that x3 - 1 = 7 is a prime number
But if: x2 + x + 1 = 1 then x = 0 or x = -1
Here, x3 - 1 will be negative so it will not possible.
So that, x = 2
