answer:
the answers are undefined and zero ( and in that order )
Explanation:
for question 12,
x = 10
since that equation is just a vertical line, the slope is undefined!
but for question 13
y = -5
the equation is just a horizontal line rather then a vertical line, the slope is zero ( since it is not moving )
i hope this helps you and if you need anymore help then please feel free to ask me! :)