1MS : 2.5.21 n

[2, 3,  4, 47]
[3, 5, -4,  2]
[4, 7, -2, 31]

L_2 <- 2 * L_2

[2,  3,  4, 47]
[6, 10, -8,  4]
[4,  7, -2, 31]

L_2 <- L_2 - 3 * L_1

[2, 3,   4,   47]
[0, 1, -20, -137]
[4, 7,  -2,   31]

L_3 <- L_3 - 2 * L_1

[2, 3,   4,   47]
[0, 1, -20, -137]
[0, 1, -10,  -63]

L_3 <- L_3 - 1 * L_2

[2, 3,   4,   47]
[0, 1, -20, -137]
[0, 0,  10,   74]

L_3 <- 1/10 * L_3

[2, 3,   4,   47]
[0, 1, -20, -137]
[0, 0,   1, 37/5]

L_2 <- L_2 + 20 * L_3

[2, 3, 4,   47]
[0, 1, 0,   11]
[0, 0, 1, 37/5]

L_1 <- L_1 - 4 * L_3

[2, 3, 0, 87/5]
[0, 1, 0,   11]
[0, 0, 1, 37/5]

L_1 <- L_1 - 3 * L_2

[2, 0, 0, -78/5]
[0, 1, 0,    11]
[0, 0, 1,  37/5]

L_1 <- 1/2 * L_1

[1, 0, 0, -39/5]
[0, 1, 0,    11]
[0, 0, 1,  37/5]