If a phone card is used to make a long distance phone call, you are charged $0.50 per call plus an additional $0.31 per minute.
Part A: Write an equation that can be used to find the total cost of a phone call that lasts for m minutes.
Part B: Shalon was charged $5.15 after using a phone card to make a phone call. For how many minutes did he talk on the phone?
0.50 + 0.31m
Part B -- what do you think?
Part A:
To find the total cost of a phone call that lasts for m minutes, we need to add the cost for the call and the cost per minute. The cost for the call is a fixed amount of 0.50, and the cost per minute is 0.31 multiplied by the number of minutes, m. Therefore, the equation to find the total cost would be:
Total Cost = 0.50 + (0.31 * m)
Part B:
To find the number of minutes Shalon talked on the phone, we need to solve the equation mentioned above. We know that the total cost was $5.15, so we can substitute that value and solve for m.
0.50 + (0.31 * m) = 5.15
To isolate m, we can subtract 0.50 from both sides:
0.31 * m = 4.65
Then divide both sides by 0.31:
m = 4.65 / 0.31
Simplifying this calculation gives us:
m = 15
Therefore, Shalon talked on the phone for 15 minutes.