Réponses

2014-05-25T15:58:32+02:00
2x - 3y = 0
x - 4y - 7 = 0

2x-3y = 0
x-4y = 7

2x-3y = 0
-2x+8y = -14  on multiplie celle-ci par -2

on addtionne
2x-3y-2x+8y = -14
5y = -14
y = -14/5

2x +3*14/5 = 0
2x = -42/5
x = -42/(2*5)
x = -21/5