Answer:
Step-by-step explanation:
That'd be the Substitution Property. Substitute -2 for x in x + 8 = 6 and arrive at the true statement 6 = 6.
21. >
22. Distributive Property
Answer:
14
20
18
24
Step-by-step explanation:
36 = 6 x 6
16 = 4 x 4
25 = 5 x 5
All others are not square
Answer: (-6, 5)
<u>Step-by-step explanation:</u>
Use the Midpoint Formula: 
Separate the x's and y's and solve them individually:

So, the k-coordinate is (-6, 5)
I would say that the answer is D 21.63