a)
2 (3 - 2x) - 4 = 3 (2x + 1) + 5
6 + 4x - 4 = 6x + 3 + 5
2 - 4x = 6x + 8
2 - 4x - 6x = 8
- 4x - 6x = 8 - 2
- 10x = 8 - 2
- 10x = 6 // : - 10
x = - 6/10 = - 3/5
b)
9x + 3 = 7 (x - 2) + 17
9x + 3 = 7x - 14 + 17
9x + 3 = 7x + 3
9x = 7x
9x - 7x = 0
2x = 0 // : 2
x = 0
c)
1/5x + 2 = 1/4x + 1
4x + 40 = 5x + 20
4x - 5x + 40 = 20
4x - 5x = 20 - 40
- x = - 20
x = 20
