1)
3х + 10 = 5х
3х - 5х = - 10
- 2х = - 10
х = - 10 : (- 2)
х = 5
--------------------------
3 * 5 + 10 = 5 * 5
15 + 10 = 25
25 = 25
2)
- 100 + 4х = 15
4х = 100 + 15
4х = 115
х = 115 : 4
х = 28,75
--------------------------------
- 100 + 4 * 28,75 = 15
- 100 + 115 = 15
15 = 15
3)
- 8 + 2х = 14
2х = 8 + 14
2х = 22
х = 22 : 2
х = 11
-------------------------
- 8 + 2 * 11 = 14
- 8 + 22 = 14
14 = 14
4)
х + 3 = 8х
х - 8х = - 3
- 7х = - 3
х = - 3 : (- 7)
х = 3/7
------------------------
3/7 + 3 = 8 * 3/7
3 3/7 = 24/7
3 3/7 = 3 3/7