It is 9*9 21 times so
9*9*9*9*9*9*9*9*9*9*9*9*9*9*9*9*9*9*9*9*9=
1.09418989e20 is the answer.
A I guess (finger crossed )
Biased because the survey was conducted in a limited field of people aka health club which does not include other people, perhaps an unhealthy club? Or the people who are not a part of the health club? Or people who do not care about their health?
In the
plane, we have
everywhere. So in the equation of the sphere, we have

which is a circle centered at (2, -10, 0) of radius 4.
In the
plane, we have
, which gives

But any squared real quantity is positive, so there is no intersection between the sphere and this plane.
In the
plane,
, so

which is a circle centered at (0, -10, 3) of radius
.
Answer:
a. 7 by 21
b. a(-12, 2), b(-12, -5), c(9, -5)
Step-by-step explanation:
AD is 3 times the length of AB. X can be the length of AB. Then 3x would be the length of AD. The perimeter is 56, which would also be 3x + x + 3x + x which is 8x. This gives us 8x = 56, meaning that x is 7, or the length of AB is 7. Because AD is 3 times the length of AB (which is 7), AD = 21. Therefore, the dimensions of the rectangle ABCD is 7 by 21.
Coordinates of A have to be 21 units away from D since AD = 21. It goes in the left direction, meaning that 21 is subtracted from 9 (since this is a horizontal edge involving x coordinates) while the y value remains the same. The result is (-12, 2). For coordinate B, it has to be 7 units away from A downwards since AB = 7. This means that you subtract 7 from 2 (involving only the y coordinates), resulting in (-12, -5). For coordinate C, it has to be 21 units from B since BC = AD = 21. Because C is right compared to B, you have to add 21 to -12 (involving only the x coordinate) resulting in (9, -5).