Beantwortet: Es seien A und b mit c Element R

[1, 1, 1, 7]
[2, 5, 3, 16]
[3, 7, 9, 28]
[4, 10, 8, c]

[1, 1, 1, 7]
[0, 3, 1, 2]
[0, 4, 6, 7]
[0, 6, 4, c - 28]

[1, 1, 1, 7]
[0, 3, 1, 2]
[0, 0, 14, 13]
[0, 0, 2, c - 32]

[1, 1, 1, 7]
[0, 3, 1, 2]
[0, 0, 14, 13]
[0, 0, 0, 237 - 7·c]

237 - 7·c = 0 --> c = 237/7