2. A solar lease customer built up an excess of 6,500 kilowatt hours (kwh) during the summer using his solar panels. When he turned his electric heat on, the excess began to be used up at a rate of 50 kilowatt hours per day. (a) If E represents the excess left and d represents the number of days since the heat has been turned on, write an equation for E in terms of d. (b) How much of the excess will be left after one month (use a month length of 30 days)? (c) If the heat will need to be turned on for 5 months, will the excess be enough to last through this time period? Justify your answer.​