Call Wireless phone company charges $0.50 for the first call you make and $0.10 for each additional minute. The cost of a phone call can be expressed by the formula C = 0.50 + 0.10(m – 1), where C is the total cost in dollars and m is the number of minutes that you talk. If the bill for your phone call was $1.90, how long did you talk?

Question

anonymous · Answer

1.90= 0.50 + 0.10(m - 1)
1.90= .50 + .10m - .10
1.90 - .40 = .40 - .40 + .10m
1.50= .10m
1.50/.10= .10m/.10
m=15
So 15 minutes!