1. Construct a matrix representation of the following system of equations, and solve it using the matrix:

$$ \begin{eqnarray} -3x + 6y - 9z &=& 3\\ x - y - 2z &=& 0\\ 5x + 5y - 7z &=& 63 \end{eqnarray} $$

Solution: $$ x = 8, y = 6, z = 1 $$

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