Let the first plan be represented by the function [tex]f(x) = 3.75 + x0.07[/tex] where x is the number of texts sent. We can then set this function to 16 and solve for x to find how many texts can be sent.
[tex]16 = 3.75 + x0.07[/tex]
[tex]12.25 = x0.07[/tex]
[tex]175 = x[/tex]
So, for the first plan to cost exactly 16 dollars, you would need to send 175 texts. Anything 176 or over wound cost more than the second plan.
