Question

what are the coordinates of that center of a circle if the endpoints of its diameter are a(8,-4) and b(-3,2)?

Answer 1

You need to add 8 and -3 together to get 5 and divide 5 by 2 to get 2.5
That is the x coordinate
You then need to add 2 and -4 together to get -2 and divide by 2 to get -1
This is the y coordinate
(2.5,-1)