Determine the augmented matrix for each system of linear equations:
[A.] 5x1 + 7x2 + 8x3 = 3
-2x1 + 4x2 + 9x3 = 3
3x1 - 6x2 + x3 = 1
[B.] 3x1 - 2x2 + 2x3 = 7
5x1 + 7x2 + 3x3 = 3
-5x1 + 6x2 - 8x3 = -5
[C.] 4x1 + x2 - 7x3 = 6
5x1 + 7x2 + 2x3 = 3
5x1 + 2x2 + 5x3 = 7