A student was asked to remove all possible common factors from the following rational expression: . The student wrote: . Identify the mistake, if any.
You are not allowed to cancel the x2 and 2x terms that way. In order to cancel them, common factors must be factors of every term in both the numerator and denominator of the rational expression. Just because something looks like it should work a certain way doesn't mean that's the case. Try telling that to your grandmother and her TV remote.