Question

The local electric company uses the following method for computing monthly electric bills for one class of customers. A monthly service charge of $5 is assessed for each customer. In addition, the company charges $0.095 per kilowatt hour. If c equals the monthly charge stated in dollars and k equals the number of kilowatt hours used during a month:

(a) Determine the function which expresses a customer's monthly charge as a function of the number of kilowatt hours.

(b) Use this function to compute the monthly charge for a customer who uses 850 kilowatt hours. 

Answer 1

Solution;

(a)

We write the linear equation for C;

$C=f(k)=5+0.095k$

(b)

Using f(k)

k=850

$C=f(850)=5+(0.095×850)$

$C=$ $$85.75$