math
posted by ReRe on .
When making a telephone call using a calling card, a call lasting 3 minutes cost $1.65. A call lasting 11 minutes cost $4.85. Let y ba the cost of making a call lasting x minutes using a calling card. Write a linerar equation that models the cost of making a call lasting x minutes.

The perminute charge is $3.20/8 = 40 cents.
Assume there is an additional connection charge (A) and fit an equation of the form
Cost = A + 0.40 t
to the existing data. The cost will be in dollars and t must be in minutes.