Sagot :
Bonjour
Résoudre les équations d'inconnue x suivantes
b. 4x - 21 = 7x - 9
4x - 7x = - 9 + 21
- 3x = 12
x = - 12/3
x = - 4
d. 7x + 13 = - 3x - 7
7x + 3x = - 7 - 13
10x = - 20
x = - 20/10
x = - 2
a. - 2x + 7 = -x + 9
- 2x + x = 9 - 7
- x = 2
x = - 2
C. – 7x – 12 = 8x + 3
- 7x - 8x = 3 + 12
- 15x = 15
x = - 15/15
x = - 1.
Réponse :
Bonjour,
4x - 21 = 7x - 9
4x - 7x = -9 + 21
-3x = 12
x = 12/-3
x = -4
7x + 13 = -3x - 7
7x + 3x = -7 - 13
10x = -20
x = -20/10
x = -2
-2x + 7 = -x + 9
-2x + x = 9 - 7
-x = 2
x = -2
-7x - 12 = 8x + 3
-7x - 8x = 3 + 12
-15x = 15
x = 15/-15
x = -1