Answer:
( -2,-3) is the midpoint
Step-by-step explanation:
To find the x coordinates of the midpoint, add the x coordinates of the endpoints and divide by 2
( -1+-3)/2 = -4/2 =-2
To find the y coordinates of the midpoint, add the y coordinates of the endpoints and divide by 2
( 3+-9)/2 = -6/2 =-3
( -2,-3) is the midpoint