Diophantus (250 AD)

Diophantus lived in Alexandria. His book Arithmetica is considered the first book on algebra. In it he gives methods for finding integer solutions of algebraic equations. Arithmetica was read and studied for more than a thousand years. Fermat made some of his most important discoveries while studying this book. Diophantus' major contribution is the use of symbols to stand for the unknowns in a problem. Although his symbolism is not as simple as what we use today, it was a major advance over writing everything in words. Our common algebraic notation did not come into common use until the 17th century.