1. 2x-6 = 0 → 2x = 6 → x = 6:2 → x = 3
2. 12+3x = 0 → 3x = -12 → x = -12/3 → x = -4
3. -x+7 0 → -x = -7 → x = 7
4. 15-3x=0 → 15 = 3x → x = 5
5. 3x+1=7 → 3x = 7-1 → 3x = 6 →x= 6:3 → x = 2
6. 5-2x=1 → -2x= 1-5 → -2x=-4→ 2x = 4 → x = 4:2 → x = 2
7. 5x-2=1 → 5x = 1+2 → 5x = 3→ x = 3:5 → x = 3/5 доводим до дроби 6/10 и x = 0,6
8. -5x-2=-12 → -5x = -12+2 → -5x = -10→ → x= -10:-5 → x = 2