To be clear: yequalsx said Anyone who thinks of using x-intercepts to explain this probably has had some College Algebra. The topic in the article is usually covered in Beginning Algebra. So x-intercepts are taught in middle school, but the idea of using them to explain this particular problem probably wouldn't occur to someone with such little experience.

Indeed, college algebra students typically struggle when trying to tie in the concepts of factoring, x-intercepts, remainder theorem, and zeros of a polynomial. Lots of gnashing of teeth in this chapter.

"College algebra" is usually taken by people who haven't had algebra, geometry and trigonometry classes in middle or high school. If you had all those classes, many colleges allow you to enroll in calculus as a freshman (sometimes you have to take a placement test), or you can even skip some of the calculus sequence with AP credit.

College algebra isn't something that a lot of math, science and engineering majors take, especially if they're toward the top of the class and haven't taken the easy road in their high school course selections.