<u>Hello:</u>
<u />
<u>Okay, this problem should be taken in a series of steps</u>:
<u>What is the slope's formula?</u>
- (x₁,y₁) -- first point
- (x₂,y₂) -- second point
<u>Okay, now let's use this knowledge</u>
10. (5,-19) and (-5,21)
11. (12,1) and (12, -1)
12. (8,7) and (4,7)
<u>Answer:</u>
- Question 10: -4
- Question 11: undefined
- Question 12: 0
Hopefully that helps!