Réponse :
Bonjour,
Exercice 1:
1) x - 7 = - 12
x = - 12 - (-7 )
x = - 12 + 7
x = - 5
2) 7x = 8 + 6x
7x - 6x = 8
x = 8
3) 11x - 5 = 10x + 7
11x - 10x = 7 - (-5)
x = 7 + 5
x = 12
Exercice 2:
1) 5x = - 17
x = [tex]\frac{-17}{5}[/tex]
x = -3,4
2) [tex]\frac{x}{4}[/tex] = - 11
4* = 4 (−11)
x = - 44
3) [tex]\frac{5}{3}[/tex]x = - 15
3* [tex]\frac{5x}{3}[/tex] = 3*(-15)
5x = - 45
x = [tex]\frac{-45}{5}[/tex]
x = - 9
