Answer:
D(4,-3)
Step-by-step explanation:
Given three of the vertices of the square: A(4, -7), B(8, -7),C(8, -3)
Let the coordinate of the fourth vertex be D(x,y).
We know that diagonals of a square are perpendicular bisector. So, the midpoint of both diagonals is the same.
The diagonals are BD and AC
Midpoint of BD = Midpoint of AC

The coordinates of the fourth vertex is D(4,-3)
Is this what you mean this is what i understood.
X-4=10;4x+1=57
First equation solve for x.
X-4=10
Add 4 both sides
X=10+4
X=14
Second equation substitute your x answer into second equation to make both sides equal.
4x+1=57
4(14)+1=57
56+1=57
57=57
$8 + $7 + $13 + 15 = $43
$x - $43 = $12
x = $55
i am a mathematics teacher. if anything to ask please pm me
Answer:
Coordinates of the midpoint are (-5.5, 5)