11.13 Determine for which values of $x$ the equality $\left|x^{2}-8 x+12\right|=x^{2}-8 x+12$ holds.

Solve the equations (11.14-11.15):
11.13 According to the definition of the modulus, $|a|=a$, if $a \geq 0$. Solving the inequality $x^{2}-8 x+12 \geq 0$, we establish that $x \leq 2$ or $x \geq 6$.

Answer: $(-\infty, 2] \cup[6, \infty)$