Решите уравнение:
а) (6 + 2x) + x = 9;
б) 8 + 4x + x = 18;
в) x + 2 + 3x = 14.
(6 + 2x) + x = 9
6 + 2x + x = 9
3x = 9 − 6
3x = 3
x = 3 : 3
x = 1
8 + 4x + x = 18
5x = 18 − 8
5x = 10
x = 10 : 5
x = 2
x + 2 + 3x = 14
4x = 14 − 2
4x = 12
x = 12 : 4
x = 3