Question

qual o resultado de -x²+4x-4=0  ?

Answer 1

Δ = b² -4ac
Δ = 4² -4 *(-1) * (-4)
Δ = 16 -16
Δ = 0 ( Duas raízes reais e iguais)
x' = (-b + √∆)/ 2a
(-4 + 0)/2 * (-1)
(-4 + 0)/-2
-4/-2
2
x'' = (-b - √∆)/ 2a
(-4 - 0)/2 * (-1)
(-4 - 0)/-2
-4/-2
2

S={2,2}

Answer 2

$-x^{2}+4x-4=0$

$a = -1 \\ b=4 \\ c=-4$

$\Delta=b^{2}-4*a*c \\ \Delta=4^{2}-4*(-1)*(-4) \\ \Delta=16-16 \\ \Delta=0$

$x = (-b\pm\sqrt{\Delta})/2a \\ x=(-4\pm\sqrt{0})/(2*[-1])$
$x=(-4)/(-2) \\ x=2$

S = {2}