Answer:

Step-by-step explanation:
we know that
In a rectangle, the two diagonals are congruent and each diagonal bisects the other
so
----> equation A
-----> equation B
step 1
Find the value of x
solve equation A

substitute the given values

solve for x

step 2
Find the value of KE

substitute the value of x

Remember that
-----> by each diagonal bisects the other
therefore

Answer:
D.
Step-by-step explanation:
??????????????????????????????//
The answer is (-6, 5) for K.
In order to find this, we must first note that to find a midpoint we need to take the average of the endpoints. To do this we add them together and then divide by 2. So, using that, we can write a formula and solve for each part of the k coordinates. We'll start with just x values.
(Kx + Lx)/2 = Mx
(Kx + 8)/2 = 1
Kx + 8 = 2
Kx = -6
And now we do the same thing for y values
(Ky + Ly)/2 = My
(Ky + -7)/2 = -1
Ky + -7 = -2
Ky = 5
This gives us the final point of (-6, 5)