It is shared. It's just that everyone has to go through to mental work to truly understand. It takes me a semester to convince my students that 3x+5x=8x and t

It is shared. It's just that everyone has to go through to mental work to truly understand. It takes me a semester to convince my students that 3x+5x=8x and that this is true because of the distributive property. And this is why ax+2x = (a+2)x. And the reason we can't simplify further is because our language does not have a word for (a+2) but it does have a word for (3+5). But I know that after a semester of teaching this most still don't actually understand the distributive property. It takes a lot of effort on the part of students for the concept to click.