Question

Solução de x2 + 3x - 18 = 0

Answer 1

x² + 3x - 18 = 0

Δ = b² - 4a.c

Δ = 3² - 4.1.(18)

Δ = 9 + 72

Δ = 81

√Δ = ± 9

x = (- b ± √Δ)/2a

x = (- 3 ± 9) / 2

x' = - 6

x'' = 3

Respostas:

x = - 6

x = 3

Answer 2

Resposta:

$x^{2}+3x-18=0\\\\\Delta=(b)^{2}-4(a)(c)=(3)^{2}-4(1)(-18)=9-(-72)=81\\\\x^{'}=\frac{-(b)-\sqrt{\Delta}}{2(a)}=\frac{-(3)-\sqrt{81}}{2(1)}=\frac{-3-9}{2}=\frac{-12}{2}=-6\\\\x^{''}=\frac{-(b)+\sqrt{\Delta}}{2(a)}=\frac{-(3)+\sqrt{81}}{2(1)}=\frac{-3+9}{2}=\frac{6}{2}=3\\\\S=\{-6,3\}$