Find the coordinates of the other endpoint of the segment given its midpoint and one end point pic attached

This is geometry. could anyone ? i can't fail this class. my grade is quite low already.

Complex numbers multiply √-4 * √-25 and show all intermediate steps. alternative notation is sqrt(-4) * sqrt(-25).

Which expression demonstrates the use of the commutative property of addition in the first step of simplifying the expression (-1+i)+(21+5i)+0