Question 1003717
x = number of minutes.
you equation is 5 + .05*x < .07*x


subtract .05*x from both sides of this equation to get 5 < .07*x - .05*x.


simplify this to get 5 < .02*x


divide both sides of this equation by .02 to get 5/.02 < x


solve for x to get 250 < x


this is the same as x > 250.


your cost per call will be less than 7 cents a call when the number of calls is greater than 250.


for example:


when x = 200, 5 + .05*x = 5 + 10 = 15 / 200 = .075 per call.


when x = 250, 5 + .05*250 = 5 + 12.5 = 17.5 / 250 = .07 per call.


when x = 300, 5 + .05*300 = 5 + 15 = 20 / 300 = .067 per call.


any number of calls less than 250 results in a cost per call greater than .07
250 calls results in a cost per call exactly equal to .07.
any number of calls greater than 250 results in a cost per call less than .07.


you have to talk more than 250 minutes in a month for your cost per call to be less than .07.