If the coordinates of the mid-point of the line segment joining the points (2,1) and (1,-3) is (x, y) then the relation between x and y can be best described by
6x + y = 8
From section formula if (x, y) are the midpoints of the line segment joining (x1,y1) and (x2,y2), then
x = x1+x22 and y = y1+y22.
So, x = 32 and y = -1.
Just check that which of the given equation satisfies for x = 32 and y = -1