Answer/Step-by-step explanation:
7. Line 1 = undefined.
Slope of a vertical line is always undefined. The run is zero as x-coordinate remains the same.
8. Line 2 =
9. Line 3 =
10. Line 4 = undefined (slope of a vertical line is always undefined)
11. Line 5 =
12. Line 6 =
13. Line 7 = 0
An horizontal line has no rise.
14. Line 8 = 0 (slope of horizontal line is always zero)
15. Line 9 = undefined (slope of a vertical line is always undefined)
16. Line 10 = undefined (slope of a vertical line is always undefined)
17. Line 11 = 0 (slope of horizontal line is always zero)
18. Line 12 = undefined (slope of a vertical line is always undefined)
