To factor the quadratic expression \( x^2 - 12x + 27 \), we can look for two numbers that multiply to \( 27 \) (the constant term) and add to \( -12 \) (the coefficient of the \( x \) term).
The two numbers that meet these criteria are \( -3 \) and \( -9 \) since:
- \((-3) + (-9) = -12\)
- \((-3) \times (-9) = 27\)
Therefore, we can write the factorization as:
\[
x^2 - 12x + 27 = (x - 3)(x - 9)
\]
So, the factored form of \( x^2 - 12x + 27 \) is:
\[
(x - 3)(x - 9)
\]