Solve the system of equations using augmented matrix methods.

$x_1-3x_2=-5$

$3x_1-x_2=9$

Select the correct choice below and, if necessary, fill in the answer box to

A$.$ The unique solution to th $2$ system is $x_1=$ and $x_2=.($Simplif$)$

B$.$ There are infinitely many solutions. The solution is $x_1=$ and $x_2$

C$.$ There is no solution.