Question 1:
For this one, we can use the midpoint formula.
[tex](\frac{x_1+x_2}2, \frac{y_1+y_2}2)[/tex]
[tex](\frac{-4+8}2, \frac{8+(-4)}2)[/tex]
[tex](2,2)[/tex]
The second choice is your answer
Question 2:
If you draw this on the coordinate plane, we have a right triangle with legs of 12 and 9. This is similar to a 3-4-5 right triangle.
Thus, the lengths 9, 12, and 15.
9 + 12 + 15 = 36
Your answer is the last choice. Have an awesome day! :)