Hey there!
To find the x-value of the midpoint, you add the two x-values of the endpoints and the divide the result by two.
-12+0=-12
-12/2=-6
So, the x-value of our midpoint is -6.
To find the y-value of a midpoint, you do the same thing as with the x-values but with the y-values.
2+14=16
16/2=8
Our y-value is 8.
Therefore, our midpoint is (-6,8)
I hope that this helps!