There is a past question that wasn't solved. It's in the Advanced Maths category. I'm still curious to see the final answer, if anyone can figure how to do it.

Here's that question again: http://web2.0calc.com/questions/wilson-s-theorem

Badinage
May 11, 2015

#1**+5 **

One last attempt at posting this.The software on this system is hopeless.

We can write 36x27!+25 as (36x31!+(31x30x29x28)x25)/31x30x29x28 and can now factor out 31 from the numerator.So the expression is divisible by 31 and we can write

36x27!+25=31n for some n.

then,to use Wilson,we can write 36x27!+25=31!n/30! and since 31!=30mod 31 ,rearrange to get

n=30!(36x27!+25)/30modulo31 which is divisible by 31.

hope this helps.

Mathcad
May 11, 2015