Bonsoir,
Voici les résultats :
1. 17x - 12 = 21x + 7
<=> -19 = 4x
<=> -4,25 = x
2. -x -7 = -9x -5
<=> x +7 = 9x +5
<=> 2 = 8x
<=> 2/8 = x
3. 4(x +1) = 10(x -7)
<=> 4x +4 = 10x -70
<=> 74 = 6x
<=> 37/3 = x
Voilà tout, n’hésite pas si tu as des questions.
