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Pythagorean Theorem Found On Clay Tablet 1,000 Years Older Than Pythagoras
(www.iflscience.com)
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There are mentions of pythagorian triplets in pyramid era Egypt, and in all fairness, ancient Greeks didn't have symbolic algebra either - it is a fairly recent form of expression.
And, as far as I know, ancient Indians were actually writing mathematical expressions in full prose form - word problems et al.