<image>Yesterday morning, Uncle Zhang brought the bitter gourds he planted into the city to sell. For convenience, he brought along some spare change. Uncle Zhang first sold some bitter gourds at the market price and then started to reduce the price at 11 am for clearance . It is known that the amount of money S (including spare change, in yuan) he had and the amount of bitter gourds sold x (in kilograms) have a relationship as shown in the figure.
(1) What is the amount of spare change Uncle Zhang brought with him?
(2) When Uncle Zhang sold the remaining bitter gourds at 2 yuan per kilogram, he had 52 yuan in hand (including spare change). How many kilograms of bitter gourds did Uncle Zhang sell in total yesterday?
(3) Find the functional relationship between the amount of money S (including spare change) Uncle Zhang had and the amount of bitter gourds sold x before he started to reduce the price at 11 am.