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Answer:
19
Step-by-step explanation:
Matt ended up with 26.
We reverse the steps he did to get the original number that both people thought of.
26 / 2 = 13
13 - 7 = 6
6 is the original number.
Tikka did the same operations but in the reverse order so...
6 X 2 = 12
12 + 7 = 19
Answer:
See Explanation
Step-by-step explanation:

Answer: (0, -6)
Step-by-step explanation:
The center is the midpoint of the diameter, meaning that the coordinates of Y must be (0, -6).