Answer:
(-6 , 3)
Step-by-step explanation:
Co-ordinates of A = (-9,-1)
So let x¹ = -9 & y¹ = -1
Co-ordinates of B = (-3,7)
So let x² = -3 & y² = 7
According to Section formula ,

where (x' , y') are the co-ordinates of the point which divides a line segment internally & (m , n) are the ratios in which the line is divided into.
As we have to find the co-ordinates of mid-point of AB , here m = n = 1 (∵ A mid-point always divides a line segment into 2 equal parts. Hence the ratio of length of both lines will be 1 : 1 )
Putting the values in the above formula gives :

∴ Co-ordinate of M = (-6 , 3)