Question

A phone company charges $.25 for the first minute of a long distance call and$.07 for each addition minute. write an equation that gives the cost C of a long distance call as a function of the length t (in minutes) of the call. find the duration of a long distance cap that costs $2 Answers 1. Tryphena The cost C of a long distance call as a function of the length t is C(t) = 0.25 + 0.07t and the number of minutes is 25 minutes ### What are linear equations? Linear equations are equations that have constant average rates of change. Note that the constant average rates of change can also be regarded as the slope or the gradient ### How to determine the solution to the system? A system of linear equations is a collection of at least two linear equations. In this case, the given parameters are: Charge for first minute =$.25
Rate for additional minute = $.07 per minute Let the number of minutes be t and the total cost be C(t) So, we have: C(t) = Charge for first minute + Rate for additional minute * x This gives C(t) = 0.25 + 0.07t When the total cost is$2, the equation becomes
0.25 + 0.07t = 2
Subtract 0.25 from both sides
0.07t = 1.75
Divide both sides by 0.07
t = 1.75/0.07
Evaluate the quotient
t = 25
Hence, the number of minutes is 25 minutes