Diophantus and his Algebra

None of the Greek mathematicians mentioned him to the IV century, so he probably lived in the middle of the III century. The main work of Diophantus "Arithmetic" (Ἀριθμητικά), at first consisted of 13 "books" (βιβλία), i.e. Chapters. We now have 10 of them, namely 6 in the Greek text, and another 4 in the medieval Arabic translation, whose place in the middle of Greek books: Books I-III in Greek, IV-VII in Arabic, VIII-X Greek. "Arithmetic" by Diophantus primarily is a collection of tasks, a total of about 260. To say the truth, there is no theory there, only general instructions in the book's introduction, and private notes in some problems when you need to. "Arithmetic" already has the features of an algebraic treatise. First, Diophantus use different characters to express an unknown value and its powers, also some calculations; like all algebraic symbols of the Middle Ages, his symbolism is derived from the mathematical words. Then, Diophantus explains how to solve the problem of algebraic way. But Diophantus' problems are not algebraic in the usual sense, because almost everything is reduced to the solution of indeterminate equations or systems of such equations.