Exercice 4 voir pièce jointes
[tex]\left \{ {{x + 4y = 2} \atop {3x-2y = -8}} \right.\\ \\ x = 2 - 4y\\ \\ 3(2-4y) - 2y = -8\\ 6 - 12y - 2y = -8\\ -14y = -8-6\\ 14y = 14\\ y = 1\\ \\ x= 2 - 4 = -2 [/tex]
[tex]\left \{ {{3x - 2y = -18} \atop {5x+3y = 8}} \right.\\ \\ 9x - 6y = -54\\ 10x+6y=16\\ \\ (1) + (2) : \\ 9x + 10x = -54 + 16\\ 19x = -38\\ x= -\frac{38}{19}\\ x=-2\\ \\ -10 + 3y = 8\\ 3y = 18\\ y = 6[/tex]
En espérant t'avoir aidé.
