(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

[PLAIN]http://img844.imageshack.us/img844/2975/31668142.gif [Broken]

3. The attempt at a solution

I know the inverse would be of the form:

[tex]M^{-1}_{a,p}=\frac{1}{1-(p-1)(10 \bmod\ p)} \begin{bmatrix} 1&-(a \bmod\ p)\\ -(p-1)& 1 \end{bmatrix}[/tex]

Where [tex]1-(p-1)(10 \bmod\ p)[/tex] is the determinant. Whatever this equals to, I must find its inverse.

But how does one evaluate [tex]10 \bmod\ p[/tex] and [tex](p-1)[/tex] when [tex]p \in \{ 3,7 \}[/tex]? Do we take '10 mod 7' or '10 mod 3'? I appreciate if anyone could show me that.

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# Homework Help: Matrix groups

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