# Math Help - Help!

1. ## Help!

x^329 =(congruent)=452 mod 31

2. Originally Posted by mivanova
x^329 =(congruent)=452 mod 31
Notice that $x^{329} = \left( x^{30} \right)^{10} x^{29}\equiv x^{29} (\bmod 31)$
Also, $452 \equiv 18(\bmod 31)$.
Therefore, $x^{29} \equiv 18 (\bmod 31)$.
Multiply by $x$ to get $18x\equiv 1(\bmod 31)$
Can you solve this congruence?