As there is no other info given .
So we can choose any two ordered pairs whose mid point will come out to be (4,-10)
So we can one subtract a number from either x or y , and correspondingly add the same number to same variable again.
for example
we can add 2 to x and subtract 2 from x
So we get two ordered pairs as
(4-2 , -10) , (4+2, -10)
So
(2,-10) and (6,-10)
