An energy-efficient refrigerator costs $1,600. It has an expected annual electricity cost

An energy-efficient refrigerator costs $1,600. It has an expected annual electricity cost of $100.
a. Set up an expense function A(x) to represent the cost of owning and operating this refrigerator over a period of x years.
b. Suppose a second, less energy-efficient refrigerator is for sale at $1,200.
Let E represent the annual electricity cost for this refrigerator. Set up an expense function B(x) to represent the cost of owning and operating this refrigerator over a period of x years.
c. Set up an average yearly cost rational function, C(x), for the first refrigerator.
d. Set up an average yearly cost rational function, D(x), for the second refrigerator.
e. What would the yearly energy cost for the second refrigerator have to be so that the two rational function graphs intersect at x 5 4 years?
f. Construct the graphs of each rational cost functions on the same axes.
Interpret the graphs in terms of the average yearly cost for owning and operating each refrigerator.