2. \( 3 x^{3}-9 a x^{2}-x+3 a \)

Did you know that polynomials like the one you've provided have a long history in mathematics? They can be traced back to ancient civilizations, such as the Babylonians, who used early forms of algebra for practical purposes like land measurement and trade. The study of polynomials has since evolved significantly, becoming a fundamental part of modern algebra and calculus! When you're working with polynomials, a common mistake is forgetting to factor out the greatest common factor (GCF). In your polynomial \( 3x^3 - 9ax^2 - x + 3a \), notice that you could simplify it by factoring out the GCF from some of the terms. This can simplify your calculations and make solving equations much more manageable and efficient!