Answer:
R=9.
C=(2,-2,0).
Explanation:
Lets try to find how 
can be written in the form of 
, since then its radius R and center of coordinates C=(a,b,c) would be easily recognizable.
Since we have the terms -4x and +4y, they seem to have come from the terms 
and 
, and we would need to take care of the extra +4 by substracting then. More explicitly:
, as we had originally with the x terms
, as we had originally with the y terms
Which means:
Or, putting all together:
So our radius is 9 and the center is (2,-2,0).
Answer:
The strength of gravity decreases.
An example of that would be if you were in space; you float around because there's no gravity.
At the top of the mountain, when he tightens the cap onto the bottole, there is some water and some air inside the bottle. Then he brings the bottle down to the base of the mountain.
The pressure on the outside of the bottle is greater than it was when he put the cap on. If anything could get out of the bottlde, it would. But it can't . . . the cap is on too tight. So all the water and all the air has to stay inside, and anything that can get squished into a smaller space has to get squished into a smaller space.
The water is pretty much unsquishable.
Biut the air in there can be <em>COMPRESSED</em>. The air gets squished into a smaller space, and the bottle wrinkles in slightly.
Answer:
3 m/s
Explanation:
average speed = distance traveled / total time taken
= 6m/ 2s
= 3 m/s
