Westside Energy charges its electric customers a base rate of$4.00per month,plus14per kilowatt-hour (kWh)for the first300 kWhused and9per kWhfor all usage over300 kWh.Suppose a customer usesxkWhof electricity in one month.(a) Express the monthly costEas a piecewise-defined function ofx. (AssumeEis measured in dollars.)

E(x) =

	if 0x300
	if 300 <x

(b) Graph the functionEfor

0x600.