Answer and Explanation:
As stated in the question above, "The great Gatsby" has many symbolisms, since the author was a great believer in this literary artifice. It is important to emphasize that symbolism is a figure of speech that allows reality to be presented in a subjunctive way, through elements that represent it, but this reality is not exposed in a literal way.
One of the symbols featured in the book is the mansion where Gatsby lived. This mansion represents the greatness of the character, but the emptiness that he presented inside. That's because although Gatsby's mansion is huge, luxurious and has many parties, Gatsby was always alone and lonely in that immensity of prosperity.
A second symbol presented is the Valley of Ashes, which represents the people who were trapped between a world of wealth and a world of economic decay, created by the exploitation and corruption and illegalities that formed the economy of the 1920s. This valley also represented the separation between rich people and those who were extremely poor.