The equations are parallel because the slopes are opposite reciprocals, which means if you flip -3/2 and multiply by -1 you get 2/3.
I have no clue I’m sorry. I wish I could hell
1.linear pair
2. neither
3. vertical
4. neither
5. vertical
6. neither
7. linear pair
8. neither
Their starting from up to down not side to side
1. 3x+9-9=18-9
3x=9
x=3
2. 4x-12=20
4x-12+12=20+12
4x=32
x=8
3. x+0-0
x=0
4. x/2-2+2=9+2
x/2=11
(2)(x/2)=11(2)
x=22
5. 12x-21=3
12x-21+21=3+21
12x=24
x=2
6. 3x-15=18
3x-15+15=18+15
3x=33
x=11
7. 3x-25=14
3x-25+25=14+25
x=13
8. 3x+16=22
3x+16-16=22-16
x=2
9. 2x-8=2
2x-8+8=2+8
2x=10
x=5
10. 9x-18=9
9x-18+18=9+18
9x=27
x=3
11. x+0=0
x=0
12. 9x-8=19
9x-8+8=19+8
9x=27
x=3
If you want to check my answers
use substitution method by using the x into for each equation.