1) Solve the following system by finding an inverse matrix:

$\begin{aligned} 2x + 3y -3z &= 2 \cr y - 2z &= -1 \cr x + z &= 2 \end{aligned}$

Use the same inverse to solve the following system:

$\begin{aligned} 2x + 3y -3z &= -3 \cr y - 2z &= -3 \cr x + z &= 2 \end{aligned}$

2) Solve the following system by finding an inverse matrix:

$\begin{aligned} x - 2y + 5z &= 20 \cr 2x - 3y + 9z &= 38 \cr 2x - 4y + 11z &= 45 \end{aligned}$

Use the same inverse to solve the following system:

$\begin{aligned} x - 2y + 5z &= 4 \cr 2x - 3y + 9z &= 8 \cr 2x - 4y + 11z &= 9 \end{aligned}$

Solutions:
1) $(1, 1, 1)$, $(0, 1, 2)$
2) $(1, 3, 5)$, $(1, 1, 1)$