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## Homework Statement

.......(2 , 3)

A =

......(1 , 3)

Find the trace of A^(-1)

## Homework Equations

(a , b)................................(d , -b)

.........^(-1) = (ad-bc)^(-1)*

(c , d).................................(-c, a)

## The Attempt at a Solution

..............(3 , -3)

A^-1 = 9*

..............(-1. 2)

(In mod 26)

........... (1, -1)

=

.......... (-9, 18)

Trace of A^(-1) = 1 + 18 = 19

The solution I was given said the trace is 18 but I can't seem to find where I went wrong.

Any help would be appreciated.

(Also sorry about the horrible way I wrote the matrices)