Série 3 : exo 8

[ 2,  0, 6, 10]
[-1,  8, 5,  3]
[ 1, -2, 1,  3]

L_1 <-> L_3

[ 1, -2, 1,  3]
[-1,  8, 5,  3]
[ 2,  0, 6, 10]

L_2 <- L_2 + 1 * L_1

[1, -2, 1,  3]
[0,  6, 6,  6]
[2,  0, 6, 10]

L_3 <- L_3 - 2 * L_1

[1, -2, 1, 3]
[0,  6, 6, 6]
[0,  4, 4, 4]

L_2 <- 1/6 * L_2

[1, -2, 1, 3]
[0,  1, 1, 1]
[0,  4, 4, 4]

L_3 <- 1/4 * L_3

[1, -2, 1, 3]
[0,  1, 1, 1]
[0,  1, 1, 1]

L_3 <- L_3 - 1 * L_2

[1, -2, 1, 3]
[0,  1, 1, 1]
[0,  0, 0, 0]

L_1 <- L_1 + 2 * L_2

[1, 0, 3, 5]
[0, 1, 1, 1]
[0, 0, 0, 0]

Le système est cohérent. Il a une infinité de solutions