bonjour, svp aidez-moi (j'ai rien compris - les équations!!) a) 2x + 3 = -7 b) -3x + 7 = 10 c) 5 - 2x = 25

a.
2x + 3 = - 7
2x = - 7 - 3
2x = - 10
x = - 10/2
x = - 5

b.
- 3x + 7 = 10
7 - 10 = 3x
- 3 = 3x
- 3/3 = x
- 1 = x

c.
5 - 2x = 25
5 - 25 = 2x
- 20 = 2x
- 20/2 = x
- 10 = x

a)
2x + 3 = -7
2x  = -7 -3
2x=-10
x=-10/2
x=  - 5


b)
-3x + 7 = 10
-3x = 10 -7
-3x = 3
x= - 3/3
x= - 1


c)
5 - 2x = 25
- 2x = 25-5
- 2x = 20
x= - 20/2
x= -10