bonsoir
a) 2x + 3 = -7
2x+3-3 = -7-3
2x = -10
2x /2 = - 10/2
x = -5
b) -3x+7 = 10
-3x+7-7 = 10-7
-3x = 3
-3x /-3 = 3/-3
x = 0
c) 5-2x = 25
5-5-2x = 25-5
2x = 20
2x/2 = 20/2
x = 10
d) 1-3x = 13
1-1-3x = 13-1
-3x = 12
-3x /-3 = 12/-3
x = 9
e) 8 = 6-2x
6-2x = 8
6-6-2x = 8-6
-2x = 2
2x/-2 = 2/-2
x = 0
f) 25 = 7+4x
7+4x = 25
7-7+4x = 25-7
4x = 18
4x/4 = 18/4
x = 4.5
voila j'espère t'avoir bien aider ;)
