The telephone company offers two billing plans for local calls. Plan 1 charges $21 per month for unlimited calls and Plan 2 charges $15 per month plus $0.06 per call.
a. Use an inequality to find the number of monthly calls for which Plan 1 is more economical than Plan 2.
b. Explain the meaning of the answer to part a.
a. Let x represent the number of monthly calls.
