bonjour
c) -7 + x = 0
x = 7
d) 23 - x = -12
- x = - 12 - 23 = - 35
x = 35
e) 5x = 20
x = 4
f) -6x = 20
x = - 20/6 = - 10 /3
g) x÷(−7) = 3,2
x /7 = 3.2
x = 22.4
h) x=−2 12
comprends pas
I) 7x – 49 = 0
7 x = 49
x = 7
j) -2x + 13 = - 10
- 2 x = - 13
x = 13/2
k) 9x + 3 = - 5 - 8x
9 x + 8 x = - 5 - 3
17 x = - 8
x = - 8/17
l) 20–x = 4x+15
- x - 4 x = 15 - 20
- 5 x = - 5
x = 1