Consider the data below which represents how much a cell phone plan

charges per month for a given number of minutes for 3 different plans.

Plan A:

Plan B:

Plan C:

Minutes Cost

0

5

10 6

f(x) = x + 10

Consider u = {x|x is a negative real number}which is an empty set? o {x|x eu and x has a negative cube root}o {x|x eu and x has a negative square root}{x|x eu and x is equal to the product of a positive number and -1}{x|x eu and x is equal to the sum of one negative and one positive number?