Alocal cell phone company offers two different calling plans. in the first plan, you pay a monthly fee of $30 and $.35 per minute. in the second plan, yoy pay a monthly fee of $99 and $.05 per minute. write a system of equations showing the two calling plans.

A local cell phone company offers two different calling plans. In the first plan, you pay a monthly fee of $30 and $.35 per minute. In the second plan you pay a monthly fee of $99 and $.05 per minute. 
a. write a system of equations showing the two calling plans. 
scheme 1: monthly charges: 30 + 0.35m m = total minutes during the month 
scheme 2: monthly charges: 99 + 0.05m 

b. when is it better to use the first plan 
When you make few calls, only where unavoidable. 

c. when is it better to use the second plan. 
When you make a lot of call, literally "always on hello!" 

d. how much does it cost when the calling plans are equal? 
Question is unclear for me .