Solve the matrix equations $Ax = b$, where

a)     $A = \left[\begin{array}{cc} -6 &1\cr -6 &2 \end{array}\right], \quad x = \left[ \begin{array}{cc} x_1 \\ x_2 \end{array} \right] \text{ and } \quad b = \left[\begin{array}{c} -30\cr -30 \end{array}\right].$

The solution is:

$x_1 =$
$x_2 =$

  b)     $A = \left[\begin{array}{cc} -6 &1\cr -6 &2 \end{array}\right], \quad x = \left[ \begin{array}{cc} x_1 \\ x_2 \end{array} \right] \text{ and } \quad b = \left[\begin{array}{c} 20\cr 22 \end{array}\right].$

The solution is:

$x_1 =$
$x_2 =$

  c)     $A = \left[\begin{array}{cc} -6 &1\cr -6 &2 \end{array}\right], \quad x = \left[ \begin{array}{cc} x_1 \\ x_2 \end{array} \right] \text{ and } \quad b = \left[\begin{array}{c} 7\cr 8 \end{array}\right].$

The solution is:

$x_1 =$
$x_2 =$