To find the coordinates of point D, first determine the coordinates of point B, which is the midpoint of line segment AC. Given points A(-9, -4) and C(-1, 6), the coordinates of B are calculated as B = ((-9 + -1)/2, (-4 + 6)/2) = (-5, 1). Next, since E is the midpoint of BD and E is given as (-4, -3), use the midpoint formula to solve for D. Setting E = ((B_x + D_x)/2, (B_y + D_y)/2) leads to the equations -4 = (-5 + D_x)/2 and -3 = (1 + D_y)/2, which can be solved to find D's coordinates. The final coordinates of point D are (2, -7).