bonsoir
- 4 x + 20 = 0
- 4 x = - 20
x = 5
3 x + 3 = 4 x - 2
3 x - 4 x = - 2 - 3
- x = - 5
x = 5
x² + 1 = - x - 5
x² - x = - 5 - 1
x² - x = - 6
x² - x + 6 = 0 pas de solution connue au collège
13 = 10 - x
x = 10 - 13
x = - 3
2 x + 6 = 2 x + 6
2 x - 2 x = 6 - 6
0 x = 0
x² - 1 = 10 x - 22
x² - 10 x = - 22 + 1
x² - 10 x = - 21
x² -10 x + 21 = 0 pas de solution connue au collège