D is (-8,-16).
The midpoint is (-2,-6) so double this to end up at the other coordinates.
There’s a difference of 6 in the x coordinates.
There’s a difference of 10 in the y coordinates.
(4- -2)=6
(4- -6)=10
So, -2 minus 6 equals -8, -6 minus 10 equals -16, (-8,-16) is correct.
You can also check the midpoint to verify the new coordinates :)
