Answer:
495 combinations of 4 students can be selected.
Step-by-step explanation:
The order of the students in the sample is not important. So we use the combinations formula to solve this question.
Combinations formula:
is the number of different combinations of x objects from a set of n elements, given by the following formula.

How many combination of random samples of 4 students can be selected?
4 from a set of 12. So

495 combinations of 4 students can be selected.
Answer:
Odd
Step-by-step explanation:
The function is odd because cubic functions are always odd.
Answer:
The equation in standard form is 
Step-by-step explanation:
The distance from (-1, 12) to (-1, 8) = 4 = diameter of the circle. So, 2 = radius
The center of the circle is at (-1, 10)
The equation in standard form is 
Well if d= 20
d=2r
so 20 = 2r
r=10
is that what you wanted, or does this have to do with a circle