Respuesta :

Formula for coordinates of midpoint,

x= (x1+x2)/2
y=(y1+y2)/2,

where (x1,y1), (x2,y2) coordinates of the end-points. 

-1=(x1-8)/2
-2=x1-8
x1=-2+8
x1=6

1=(y1+4)/2
2=y1+4
y1=2-4
y1= - 2

K(6,-2)