Mary purchased a prepaid phone card for $30.00. Calls cost 20 cents a minute using this card. The credit, C (in dollars), left on the card after it is used for x
minutes of calls is given by the following.
C = 30.00 -0.20x
How much credit is left on the card after Mary uses it for 50 minutes of calls?

Since opening night, attendance at play a has increased steadily, while attendance at play b first rose and then fell. equations modeling the daily attendance y at each play are shown below, where x is the number of days since opening night. on what day(s) was the attendance the same at both plays? what was the attendance? play a: y = 8x + 191 play b: y = -x^2 + 26x + 126 a. the attendance was never the same at both plays. b. the attendance was the same on day 5. the attendance was 231 at both plays on that day. c. the attendance was the same on day 13. the attendance was 295 at both plays on that day. d. the attendance was the same on days 5 and 13. the attendance at both plays on those days was 231 and 295 respectively.