bonsoir =)
a) 2x + 1 = 13
2x = 13-1
2x = 12
x = 12/2
x = 6
b) 14 = 20 -3x
3x = 20 -14
3x = 6
x = 6/3
x = 2
c) 2x + 1/7 = 1
14x + 1 = 7
14x = 7-1
14x = 6
x = 6/14
x = 3/7
d) 3x - 5 = 2x + 10
3x - 2x = 10 +5
x = 15
e) 10x + 3 = 7x - 1
10x -7x = -1 -3
3x = -4
x = -4/3
f) 3x = 8x + 16
3x -8x = 16
-5x = 16
x = 16/-5