Answer: The coordinates of D are (-3, -7).
Step-by-step explanation:
First, we need to find the coordinates of B. In order to do that, take the average of the two points that make up the segment which are A and C.
Average of x's: -9 + -1 = -10/2 = -5
Average of y's: -4 + 6 = 2/2 = 1
Therefore, the coordinates of B are (-5, 1). Coordinates are always (x,y).
Now we can find D by noting that the E will be the average of B and D. So we can use the average equation to determine the value of D.
Average of the x's:
(B + D)/2 = E
(-5 + D)/2 = -4
-5 + D = -8
D = -3
Average of the y's:
(B + D)/2 = E
(1 + D)/2 = -3
1 + D = -6
D = -7
The coordinates of D are (-3, -7).