Crazyguy: " What I don’t understand is why the Ptolemy’s if they actually did this we don’t know for sure, contracted, some Jews to write their books into Greek? If they were not behind writting a Greek bible so to speak then why would the Jews do so, for they thought the older Hebrew language sacred so we’re told? The other question is are these writtings really Jewish and if not why make them look as if they are."
Our main source of information regarding the translation of the Septuagint, is the so-called Letter of Aristeas, which is discussed in the link below, so I won't go into some of the obvious indications that it is has a few deficiencies as an explanation.
http://www.biblearchaeology.org/post/2016/03/31/A-Brief-History-of-the-Septuagint.aspx#Article
Let's extract an important point from that article. By the time of Jesus, Greek had become the most important language of the Eastern Roman Empire and prior to Roman power, the Seleucid and Ptolemaic empires. And, the Greeks did not just live in what we now know as Greece, but also lived around the coast of Asia Minor. They were undoubtedly a very important part of the world at that time. In contrast, aside from the importance that the various brands of christianity have placed on the Jews, they were rather insignificant.
But large numbers lived in other areas of the ancient world. It is known that the city of Alexandria had a large Jewish population, as an example. Also, there were at least two Jewish temples in Egypt (that we know of), the first is the temple of Onias which was located at Leontopolis, and the other was located on the island of Elephantine, where it served a garrison of Jewish soldiers (who were in the service of the Ptolemies). In Roman times, as friction developed between the Jews and the Romans (that eventually led to the destruction of the temple in Jerusalem and Jews being expelled from Jerusalem), Jews in Egypt and some other north African locations conducted a serious guerrilla campaign against Roman forces. All these Jews likely spoke Greek rather than Aramaic, so a possible reason is that a Greek translation served these non-palestinian Jews.
And noting that the Letter of Aristeas invokes the world famous Library of Alexandria (then the largest in the world - or so it is claimed) and an associated research centre known as the Mouseion, maybe a translation of the Jewish religious books was wanted for the Library and the Mouseion, for the sake of owning a copy that could be read by Greek speaking students and teachers.
( https://en.wikipedia.org/wiki/Destruction_of_the_Library_of_Alexandria )
By the way, there were other translations of the OT into Greek, not much remains of them, but I suggest they were another indication that Jews in the Palestine area were becoming hellenised.