Answer:
C. Undefined
Step-by-step explanation:
Any vertical line is going to have an undefined slope. Plug in any two points from that line, and the formula will give you an undefined number.
Hope this helps!
5 2/5 would be converted to 5 6/15. you would then subtract the numerators and the whole numbers, giving you 3 5/15, which simplifies to 3 1/5
If they are in the same line yes. If they aren't then its considered non-collinear.