C. (8,-2), (-2,5), (6,0) is a function, because all the numbers are different unlike A, B, and D those all have the same number either in there domain or range.
The expression for doubling a number n and dividing by 3 is 2n/3.
A constant is a number that never changes value. Example:
x + 3 = 5, 3 and 5 are constants.