1. 3x + 9 = 18
3x + (9 - 9) = 18 - 9
3x = 9
(3x / 3) = 9/3
X = 3
2. 4x - 12 = 20
4x + (-12+12) = 20 + 12
4x = 32
(4x / 4) = 32/4
X = 8
3. This one isn't really clear in the pic so if you write it in the comments again I can help
4.
- 2 = 9
+(- 2+2) =( 9 + 2)
= 11
2(
) = (11)(2)
X = 22
5. 12x -21 = 3
12x + (-21 + 21) = (3 +21)
12x = 24
12x/12 = 24 / 12
X = 2
6. 3x -15 = 18
3x + (-15 + 15) = 18 + 15
3x = 33
3x/3 = 33/3
X = 11
7. 3x - 25 = 14
3x + (-25 + 25) = 14 + 25
3x/3 = 39/ 3
X = 13
8. 3x + 16 = 22
3x + (16 - 16) = 22 -16
3x = 6
3x/3 = 6/3
X = 2
9. 2x - 8 = 2
2x + (-8 + 8) = 2 + 8
2x/2 = 10/2
X = 5
10. 9x - 18 = 9
9x + (-18 + 18) = 9 + 18
9x/9 = 27/9
X = 3
11. X + 0 = 0
X + (0-0) = 0-0
X = 0
12. 9x - 8 = 19
9x + (-8 + 8) = 19 + 8
9x/9 = 27/9
X = 3
I hope this makes sense and now you understand the process of doing this and can do it on your own!