2. $x, y$ are real numbers, $z_{1}=x+\sqrt{11}+y i, z_{2}=$ $x-\sqrt{11}+y i$ ( $i$ is the imaginary unit), $\left|z_{1}\right|+\left|z_{2}\right|=$ 12 , let $u=|5 x-6 y-30|$. Then the maximum value of $u$ is $\qquad$ , the minimum value of $u$ is $\qquad$ .
2. $30(\sqrt{2}+1), 0$