The coordinates for D are (-4, -7)
First we must locate point B as it is vital to finding the midpoint of BD. To do this, we take the average of the endpoints AC since B is its midpoint.
x values = -9 + 1 = -8
Then divide by 2 for the average -8/2 = -4
y values = -4 + 6 = 2
Then divide by 2 for the average 2/2 = 1
Therefore B must be (-4, 1)
Now we know the values of E must be the average of B and D. So we can write equations for each coordinate since we know they are averages.
x - values = (Bx + Dx)/2 = Ex
(-4 + Dx)/2 = -4 ---> multiply both sides by 2
-4 + Dx = -8 ---> add -4 to both sides
Dx = -4
y - values = (By + Dy)/2 = Ey
(1 + Dy)/2 = -3 ---> multiply both sides by 2
1 + Dy = -6 ---> subtract 1 from both side
Dy = -7
So the coordinates for D must be (-4, -7)
Answer:
$100 rebate
Step-by-step explanation:
$479.99-$100.00= $379.99 or $479.99-20% =$383.99 so the $100.00 rebate a better offer
Answer:
4x+12
Step-by-step explanation:

30% of the 30 marbles is nine and 9-30 = 21 so your answer is 21
Answer:
I think its 300
but wouldn't that be like a 2 digit number like 30? scince they are only 10 blocks 10 + 10 + 10 (3×10= 30)
If you dont understand just coment.