# Thread: Algebra thing AS Level

1. ## Algebra thing AS Level

hi.

how do i prove using the difference of 2 squares that :

when you take a prime number bigger than 3, square it and then minus 1 the answer is always a multiple of 24

2. Hello,
Originally Posted by Megiarno
hi.

how do i prove using the difference of 2 squares that :

when you take a prime number bigger than 3, square it and then minus 1 the answer is always a multiple of 24

Then, remember that a prime number can only be in the form $\displaystyle 6k \pm 1$, with $\displaystyle k \text{ an integer } \ge 1$ (if it was $\displaystyle \pm$ 0, 2, 3, 4, p wouldn't be prime)