Пожалуйста помогите.........................................................

$x^2-|8.5x-16| \leq 8.5x \\\ x^2-8.5x\leq |8.5x-16| \\\ |8.5x-16| \geq x^2-8.5x$
$\left[\begin{array}{l} 8.5x-16 \geq x^2-8.5x \\ 8.5x-16 \leq -(x^2-8.5x) \end{array}$
$\left[\begin{array}{l} 8.5x-16 \geq x^2-8.5x \\ 8.5x-16 \leq -x^2+8.5x \end{array}$
$\left[\begin{array}{l} x^2-17x+16 \leq 0 \\ x^2-16 \leq 0 \end{array}$
$\left[\begin{array}{l} (x-1)(x-16) \leq 0 \\ (x+4)(x-4) \leq 0 \end{array}$
$\left[\begin{array}{l} x\in[1;16] \\ x\in[-4;4] \end{array}$
$x\in[-4;16] \\\ \Delta=|16-(-4)|=20$
Ответ: 20