if i multiply a number then there is no requirement that the number i multiply be 1.
Yes originally g*d made eve for adam but that does not preclude polygamy. Jewish OT era law permitted multiple wives in full acceptance of Genesis, hence Genesis and multiple wives were in no conflict. You are interpreting (with lack of skill).
Matthew 19 concerns itself with the topic of divorce. The topic of discussion was divorce. The Pharisees asked Jesus about divorce. The Pharisees did not ask Jesus about marriage. Pay attention! Read the bible more carefully! You don’t expect a full definition of marriage and the laws regarding marriage when asking a question about divorce! here is how to read the bible properly: don’t take things out of context. don’t interpret by placing meanings into passages that are not in the passages themselves. Interpretation is explicitly forbidden by the bible:
Proverbs 30:5-6 ESV
Every word of God proves true; he is a shield to those who take refuge in him. Do not add to his words, lest he rebuke you and you be found a liar.
Deuteronomy 4:2 ESV
You shall not add to the word that I command you, nor take from it, that you may keep the commandments of the Lord your God that I command you.
Yes it absolutely does preclude polygamy. All the examples of polygamy in Scripture are against God’s will and produced pain and suffering. The first example of a polygynist was Lamech, who married two wives, Adah and Zillah (Genesis/Bereshith 4:19); this man was a bigger sinner than Cain and openly evil, who boasted about murdering a man and declaring that God would avenge him 77-fold if he were killed for doing it (verse 24).
It is also plain that Noah and his three sons each had but one wife when they went into the ark. If God countenanced polygamy, then why would that be? Obviously polygamy is not divinely countenanced, but prohibited.