[XaspR8d]

In my rural US curriculum, these concepts were 100% part of the (very vague) "Algebra II".

Granted it seems like it didn't stick for a large segment of folks.

(Which might be a valid thing to examine in itself: for math and science we tend to act like it's just the fact that a course is missing from the curriculum that will answer why the general population is inexperienced with it, but nearly everyone also takes composition and literature classes, and I don't feel like we can say their associated skills are really at "saturated" levels.)