Question

Achar as raisez da equações ×-2×-20=0

Answer 1

Olá!!

Resolução!!

x² - 2x - 20 = 0

a = 1, b = - 2, c = - 20

∆ = b² - 4ac
∆ = ( - 2 )² - 4 • 1 • ( - 20 )
∆ = 4 + 80
∆ = 84

x = - b ± √∆ / 2a
x = - ( - 2 ) ± √84 / 2 • 1
x = 2 ± √2² • 21 /2
x = 2 ± 2√21 / 2
x' = 2 + 2√21/2
x' = 1 + √21

x" = 2 - 2√21/2
x" = 1 - √21

S = { 1 - √21 , 1 + √21 }

Espero ter ajudado!!

Answer 2

x² -2x -20 = 0

$\mathsf{\Delta=b^2-4ac}$

4 -4 * -20

84 = 21 * 2²

$\mathsf{x = \frac{-b \pm \sqrt{\Delta} }{2a}}$

2 ± 2√21/2

1 ± √21

{1 + √21 , 1 -√21}