Série 3 : exo 5

[ 1, -2, 4]
[ 4, -3, 1]
[-2,  7, h]

L_2 <- L_2 - 4 * L_1

[ 1, -2,   4]
[ 0,  5, -15]
[-2,  7,   h]

L_3 <- L_3 + 2 * L_1

[1, -2,     4]
[0,  5,   -15]
[0,  3, h + 8]

L_2 <- 1/5 * L_2

[1, -2,     4]
[0,  1,    -3]
[0,  3, h + 8]

L_3 <- L_3 - 3 * L_2

[1, -2,      4]
[0,  1,     -3]
[0,  0, h + 17]

L_1 <- L_1 + 2 * L_2

[1, 0,     -2]
[0, 1,     -3]
[0, 0, h + 17]

Il faut que  h = -17