1 - 3n = - 8 0.2x + 12 = 0.3x + 9 1 / 2x + 1 = 1 / 3x - 5

1 - 3n = - 8 0.2x + 12 = 0.3x + 9 1 / 2x + 1 = 1 / 3x - 5

① 1 - 3 n = - 8
- 3n = - 18
- 3n = 9
∴ n = 3
② 0.2x + 12 = 0.3x + 9
0.2x - 0.3x = - 12 + 9
- 0.1x = - 3
∴ x = - 30
③ 1 / 2x + 1 = 1 / 3x - 5
1 / 2x - 1 / 3x = - 1 - 5
1 / 6x = 6
∴ x = - 36