Posted by alexis on .
1.)A utility company has the following rate schedule for natural gas usage in a city’s business district:
Monthly service charge: $8.80
Per therm service charge
1st 25 therms : $0.6686/therm
Over 25 therms: $0.85870/therm
(a) What is the charge for using 25 therms in one month?
(b) What is the charge for using 45 therms in one month?
(c) Construct a function that gives the monthly charge C for x therms of gas.
I am totally lost, can someone please show me how to do this???

pre calculus 
Steve,
is using x therms,
f(x) = 8.80 + .6686x for 0<=x<=25
25 therms cost $16.715, so
f(x) = 8.80+16.715 + .85870x
= 25.515 + .85870x for 25<x
now just plug in values for x, using the appropriate function 
pre calculus 
alexis,
what do you mean when you say, "the appropriate function?" what function are you referring to?

pre calculus 
Breanna,
I mean to where I have to graph the following function using transformations. And have to be sure to graph all of the stages on 1 graph. Then I have to state the domain and range.

pre calculus 
vadivel,
f(x) = 8.80+0.6686x for 0 < x <= 25
f(x) = 25.515+0.85870(25x) for x > 25