2x + 1 = 5 |-1
2x = 4 |:2
x = 2
2x + 6 = 12 |-6
2x = 6 |:2
x = 3
4 - 2x = 10 |+4
-2x = 14
x = -7
20 - 3x = 2x + 5 |+3x
20 = 5x + 5 |-5
15 = 5x |5
x = 3
2 + 4 = 4 - 3x
6 = 4 - 3x |-4
2 = -3x
2(x + 1) = 5
2 x (x + 1) = 5
2x - 2 = 5 |+2
2x = 7 |:2
x = 3,5
3(x - 2) - 7 = 8 |+7
3 x (x - 2) = 15
3x - 6 = 15 |+6
3x = 21 |:3
x = 7
2x - (3x + 1) = 6 |-1
2x - 3x = 5
-x = 5
x = -5
2 - (5 + x) = 2(3 - x)
-3 + x = 2 x (3-x)
-3 + x = 6 - 2x |+2x
-3 + 3x = 6 |+3
3x = 9 |:3
x = 3
