$x^2+3x-4$ = 0

D = ${\left(\frac{3}{2}\right)}^2-\left(-4\right)$ = $\frac{9}{4}$$+$ $4$ = $\frac{9}{4}$$+$ $\frac{16}{4}$ = $\frac{25}{4}$

x_1,2 = $-\frac{3}{2}$ ± $\sqrt{\frac{25}{4}}$

x₁ = $-\frac{3}{2}$ - $\frac{5}{2}$ = $-\frac{8}{2}$ = -4

x₂ = $-\frac{3}{2}$ + $\frac{5}{2}$ = $\frac{2}{2}$ = 1

L = { $-4$; $1$}

$-60-4x$ = $-x^2$ | - ( $-x^2$)

$-60-4x+x^2$ = 0

sortieren

$x^2-4x-60$ = 0

D = ${\left(-2\right)}^2-\left(-60\right)$ = $4$$+$ $60$ = $64$

x_1,2 = $2$ ± $\sqrt{64}$

x₁ = $2$ - $8$ = -6

x₂ = $2$ + $8$ = 10

L = { $-6$; $10$}