Instead of subtracting 6 from 12 then dividing they added 6 to 12 & ended up with 18. 18 by 2 is 9.
Here are a bunch of CORRECT answers. Your answer is in the first pic. I got number 3 wrong, but it still showed the correct answer.
Answer:
slope = -7/4
Step-by-step explanation:
Plug the points into this formula: 
Plug in

The simplest form is -7/4
Hope this helps ya! Keep smiling!
Answer:
-2,-3
Step-by-step explanation: