Question

In December, Carlos called within Canada, to the United States, and to Mexico.

The charges are $0.28/min within Canada, $0.30/min to the U.S., and $0.84/min to Mexico if
the following conditions applied. His total bill for the month was $90.96. He talked twice as
long to Mexico as he did to the U.S. The total number of minutes spent talking within Canada
and to Mexico was 122. Write a system of equations to help you the number of minutes Carlos
called to each country.

Answer 1

m = 2u

c+m = 22
0.28c + 0.30u + 0.84m = 90.96
Now just solve the system