1. Let's clarify the problem: You asked why we didn't factor for $x^3$ in a previous problem. 2. Factoring depends on the expression given. If the expression contains $x^3$ as a common factor in all terms, then factoring it out is appropriate. 3. For example, if the expression is $x^3 + 2x^2 + x$, we can factor out $x$ (the smallest power common to all terms), not $x^3$ because $2x^2$ and $x$ do not have $x^3$. 4. The general rule is to factor out the greatest common factor (GCF) that divides all terms. 5. If $x^3$ is not common to all terms, factoring it out is incorrect. 6. Always check each term's power of $x$ and factor out the smallest power present in all terms. 7. If you provide the exact expression, I can show the factoring step-by-step.