It is very hard to determine the real contributions of the Babylonians Maths because there is very little historical evidence. In this sense, we actually consider the Greek culture as the most important of the ancient world because they had a very big evidence and texts. Altough this is not a formidable reason to believe that the Greeks are more important than Babylonians.

The babylonians developed very important Mathematics (arithmetic operations, fractional numbers, etc.) but they don't give importance to the mathematical reasoning or the logical processes (in other words, Babylonians don't care about demonstrations, reasonings, arguments to explain why the algorithms functions, etc.) While the greeks study about the demonstration and how to validate mathematical affirmations, etc. Then, today someones consider that the important thing in mathematics is demonstrations, then they consider greeks as most important. However there are communities in Mathematics (especially in Mathematical Education) that consider other aspects of Mathematics (their applications, their history, etc.) and in consecuence the greeks are very important but not the most important civilization.

In relation with Egyptians, it is well known that the Greeks take a lot of elements from the Egyptian Maths (v.g. Thales) then it is very logical that the greek maths is influenced by Egyptian maths

I hope helped you!