20. To calculate your electric bill for your home, DTE uses the following equation: C = 5 + 4e where C is how much they charge you and e is the amount of electricity used measured in kilowatt-hours (kwh) used.

a. Does this situation represent a linear function? Explain.

b. Find the domain of the function. Is the domain discrete or continuous? Explain.

c. Graph the function using its domain.