The cost, in dollars, of cellular phone service with econo-phone is given by c = 0.18x + 14.55, where x is the number of minutes used in one month. a. 0.18 signifies the cost per minute, and 14.55 signifies the monthly service charge. c. 14.55 signifies the cost per minute, and 0.18 signifies the monthly service charge. b. 0.18 signifies the hourly phone rent, and 14.55 signifies the cost of the hardware. d. 14.55 signifies the total phone bill, and 0.18 signifies the number of minutes used.

Option: a is the correct answer.

 a. 0.18 signifies the cost per minute, and 14.55 signifies the monthly service charge.

We are given a cost function in terms of x , where x is the  number of minutes used in one month as:

              C = 0.18x + 14.55

This means that the fixed monthly service charge is: $ 14.55

( Since, it represents the y-intercept i.e. when x=0 )

and 0.18 represents the slope of the given cost function i.e. it represents the cost per minute.

             Hence, the answer is:

                  Option: a

answer4 to the second power is 16

and 4 to the third power is 64,