Question: User: $8x^2$ + $18$
1. **Problem:** Simplify $8x^2 + 18$.
2. There is no like term to combine with $8x^2$, so the expression is already simplified.
3. The only useful step is to factor out the greatest common factor.
4. The greatest common factor of $8x^2$ and $18$ is $2$.
5. Factor out $2$:
$$8x^2 + 18 = 2\left(\cancel{8x^2\div 2} + \cancel{18\div 2}\right)$$
6. Simplify the factors:
$$8x^2 + 18 = 2(4x^2 + 9)$$
7. **Final answer:** $2(4x^2 + 9)$