First I have to say, I am not a scholar, forgive me if I make a mistake. But Unfortunately, you have not looked at the text in a context. I do not have the experience of reading the Quran in a professional way. However, this might be an insight and beginning to a more academic approach of reading the Quran. In order to understand the book, we need to understand in what kind of historical and geographical context we are in, and to read the comments of the Muslim scholars to understand which event that is taking place.
- If you look at the upcoming verse from the Quran that you looked at, then look at the following sentences. The following sentences elaborates that both Adam and Eve were deceived. After 20:120 comes 20:121 it is the next 'verse' or also called 'ayah' tells us that it not a matter of who is to be blamed, because both of them made the same mistake:
"So, both of them [‘Adam and Hawwa’ (Eve)] ate from it, and their parts of shame were exposed to them, and they started stitching on themselves some of the leaves of Paradise. And ’Adam disobeyed his Lord, and erred. (121)"
"So, both of them [‘Adam and Hawwa’ (Eve)] ate from it, and their parts of shame were exposed to them, and they started stitching on themselves some of the leaves of Paradise. And ’Adam disobeyed his Lord, and erred. (121)"
And a comment from the scholar, can contribute to our understanding, as you can see from the following: (Translation of the Holy Quran in English by Mufti Taqi Usmani - www.quranexplorer.com/quran)