Bonjour,
Si tu as correctement recopier ton énoncé...
3x + 1 - 4x = 7
⇔- x + 1 = 7
⇔- x = 6
⇔x = -6
2x + (3x - 6) = x + 10
⇔2x + 3x - 6 = x + 10
⇔5x - 6 = x + 10
⇔4x = 16
⇔x = 16/4
⇔x = 4
5 - (3x - 11) = -8x - 4
⇔5 - 3x + 11 = - 8x - 4
⇔- 3x + 16 = - 8x - 4
⇔5x = - 20
⇔x = -20/5
⇔x = -4
- ( x + 13) - (-8x + 12) = 13
⇔-x - 13 + 8x - 12 = 13
⇔7x - 25 = 13
⇔7x = 38
⇔x = 38/7
