Question

achar as raizes das equacoes ×^2-×-20=0​

Answer 1

Resposta:

x²-x-20=0

∆=(-1)²-4.1.-20

∆=1+80

∆=81

$x = \frac{ - ( - 1) - \sqrt{81} }{2 \times 1} = \\ x = \frac{1 - 9}{2} = \frac{ - 8}{2} = - 4 \\ x = \frac{1 + 9}{2} = \frac{10}{2} = 5$

x' = -4

x" = 5