Question

As raizes da equação x²+x-6=0 são

A){12,-13}
B){3,-2}
C)s={3,-3/2}
D)s={-3,2}

Answer 1

As raizes da equação x²+x-6=0 são

A){12,-13}
B){3,-2}
C)s={3,-3/2}
D)s={-3,2}

A = 1
B = 1
C = -6


Calcular primeiro o valor de Delta

∆ = (1)² - 4*1 -(-6)
∆ = 1 + (-4) * (-6)
∆ = 1 + 24
∆ = 25


Calculando X1

X1 = -(1) - √25/(2*1)
X1 = -1 -√25/2
X1 = -1 + 5/2
X1 = 4/2
X1 = 2

Calculando X2

X2 = -(1) - √25/(2*1)
X2 = -1 - √25/2
X2 = -1 - 5/2
X2 = -6/2
X2 = -3


RESPOSTA

S = {-3,2}


alternativa(D) S = {-3,2}

Answer 2

x²+x-6=0
Δ= -b - 4ac
Δ= -1² - 4.1.(-6)
Δ= 25

x= -b+-√Δ / 2a
x' = -1+5/2 → x'=2
x''= -1-5/2 → x''= -3    
Letra D