Question

x ao quadrado menos 4x menos 12 igual a zero

Answer 1

$x^{2} -4x-12=0$
A = 1
B = (-4)
C = (-12)

$Δ = (-4)^{2} -4.1.(-12)$
$Δ = 16 + 48$
$Δ = 64$

$x= \frac{ -(-4)+- \sqrt{64} }{2.1}$
$x= \frac{4+-8}{2}$
$x' = \frac{4+8}{2} = \frac{12}{2} = 6$
$x''= \frac{4-8}{2} = \frac{-4}{2} = -2$
$S= [6,-2]$