#### Answer

The final solution to the augmented matrix is:
1 3 0 -5
0 0 1 3
In parametric form, the solution is:
$x_{1}$ = -5 - $3x_{2}$
$x_{2}$ is free
$x_{3}$ = 3

#### Work Step by Step

We begin with the original augmented matrix:
1 3 4 7
3 9 7 6
We replace the second row by the second row plus the first row multiplied by -3.
1 3 4 7
0 0 -5 -15
We divide the second row by -5.
1 3 4 7
0 0 1 3
We then eliminate all non-zero entries except for the leading entries from every column. We replace the first row by the first row plus the second row multiplied by -4. This gives us the solution of the matrix.
1 3 0 -5
0 0 1 3