Bonjour
a)
3x= 9-4 =
3x= 5
x= 5/9
7x =-13 +1
7x= -12
x= -12/7
b)
2x=3-1
2x= 2
x= 2/2 = 1
-5x = 4+2
-5x = 6
x= -6/5
c)
3-1 = -3x
2 = -3x
x= -2/3
2+1 = 3x
3=3x
x= 3/3 = 1
d)
13x-9x =5-1
4x = 4
x= 4/4 = 1
e)
4+1 = 4x -3x
5 = x
x=5
f)
4+2 = 5x +x
6 = 6x
x= 6/6 = 1
g)
-1-1 = 3x -x
-2 = 2x
x= -2/2 = -1
h)
0,2x +0,2x = -0,2 +0,2
0,4x = 0
x= 0