Réponses

2013-10-06T18:32:56+02:00
(7x + 4) fois 3 = x + 2-> 21x + 12 = x + 2
-> 20x + 10 = 0
-> 2x + 1 = 0
-> x = -1/2
2013-10-06T18:48:06+02:00
7 (x-2)+4 (x+3)=0
7 * x + 7 * (-2) + 4 * x + 4 * 3 = 0
7x + (-14) + 4x + 12 = 0
11x = 0 + 14 - 12
11x = 14 - 12
11x = 2
x = 2/11

3 (x-4)=7 (2x-1)
3 * x + 3 * (-4) = 7 * 2x + 7 * (-1)
3x + (-12) = 14x + (-7)
3x - 14x = -7 + 12
-11x = 5
x = -5/11