$x^2+14x+50$ = 0

D = $7^2-50$ = $49$ $-$ $50$ = $-1$

Da die Diskriminante D < 0 ist, hat die quadratische Gleichung keine Lösunng.

L ={}

$20+x^2$ = $9x$ | - ( $9x$)

$20+x^2-9x$ = 0

sortieren

$x^2-9x+20$ = 0

D = ${\left(-\frac{9}{2}\right)}^2-20$ = $\frac{81}{4}$ $-$ $20$ = $\frac{81}{4}$$-$ $\frac{80}{4}$ = $\frac{1}{4}$

x_1,2 = $\frac{9}{2}$ ± $\sqrt{\frac{1}{4}}$

x₁ = $\frac{9}{2}$ - $\frac{1}{2}$ = $\frac{8}{2}$ = 4

x₂ = $\frac{9}{2}$ + $\frac{1}{2}$ = $\frac{10}{2}$ = 5

L = { $4$; $5$}