You’ve provided the quadratic expression:

$x^2 - 9x + 18$

If you're looking to factor it, we will find two numbers that multiply to $18$ (the constant term) and add up to $-9$ (the coefficient of $x$).

The two numbers that satisfy these conditions are $-3$ and $-6$, because:

$-3 \times -6 = 18 \quad \text{and} \quad -3 + -6 = -9$

Therefore, the factorization is:

$(x - 3)(x - 6)$

So, the quadratic expression factors as:

$x^2 - 9x + 18 = (x - 3)(x - 6)$

Would you like more details or an explanation of the steps?

Here are some related questions:

1. How do we apply the quadratic formula to solve $x^2 - 9x + 18 = 0$?
2. What is the discriminant, and how does it affect the solutions of a quadratic equation?
3. How can we complete the square to solve the quadratic equation $x^2 - 9x + 18 = 0$?
4. What does the graph of the quadratic function $y = x^2 - 9x + 18$ look like?
5. What are some real-life examples where quadratic equations might be used?

Tip: Always check the middle term when factoring quadratics; the sum of the factors must match the middle coefficient.