$x^2+15x+50$ = 0

D = ${\left(\frac{15}{2}\right)}^2-50$ = $\frac{225}{4}$ $-$ $50$ = $\frac{225}{4}$$-$ $\frac{200}{4}$ = $\frac{25}{4}$

x_1,2 = $-\frac{15}{2}$ ± $\sqrt{\frac{25}{4}}$

x₁ = $-\frac{15}{2}$ - $\frac{5}{2}$ = $-\frac{20}{2}$ = -10

x₂ = $-\frac{15}{2}$ + $\frac{5}{2}$ = $-\frac{10}{2}$ = -5

L = { $-10$; $-5$}

$-9x-10+x^2$ = 0

sortieren

$x^2-9x-10$ = 0

D = ${\left(-\frac{9}{2}\right)}^2-\left(-10\right)$ = $\frac{81}{4}$$+$ $10$ = $\frac{81}{4}$$+$ $\frac{40}{4}$ = $\frac{121}{4}$

x_1,2 = $\frac{9}{2}$ ± $\sqrt{\frac{121}{4}}$

x₁ = $\frac{9}{2}$ - $\frac{11}{2}$ = $-\frac{2}{2}$ = -1

x₂ = $\frac{9}{2}$ + $\frac{11}{2}$ = $\frac{20}{2}$ = 10

L = { $-1$; $10$}