One phone company advertises a flat rate of .07 per minute for long distance calls your long distance plan charges five dollars per month plus a rate of .05 per minute how many minutes do you have to talk to each month so that your average cost is less than .07 per minute
5.00 + .05x < .07x
5.00 < .02x
250 < x
So, you need to use more than 250 minutes to make it cost less
To determine the number of minutes you need to talk each month so that your average cost is less than $0.07 per minute, we can set up an equation. Let's say you talk x minutes per month.
For the first phone company with a flat rate of $0.07 per minute, the cost for x minutes would be 0.07 * x.
For the second long distance plan with a rate of $0.05 per minute, you have to pay a fixed charge of $5 per month in addition to the rate. So the cost for x minutes would be $0.05 * x + $5.
To find the point where the average cost is less than $0.07, we set up the inequality:
(0.05 * x + 5) / x < 0.07
To solve this inequality, we can simplify and isolate x:
0.05 * x + 5 < 0.07 * x
0.05 * x - 0.07 * x < -5
-0.02 * x < -5
x > (-5) / (-0.02)
x > 250
Therefore, you would need to talk more than 250 minutes per month for your average cost to be less than $0.07 per minute.