Question

(QUESTÃO 04) – Dada a equação 2x² - 8 = 0, um dos valores de x é:

a)1

b)2

c)3

d)4 ​​

Answer 1

• $\underbrace{\large{2x^{2}-8=0}}$

▶️Coeficientes:

• $\small{a=2}$

• $\small{b=\:0}$

• $\small{c=-8}$

▶️discriminante

• $\small{\Delta=b^{2}-4.a.c}$

• $\small{\Delta=(0)^{2}-4.(2).(-8)}$

• $\small{\Delta=0+64}$

• $\small{\Delta=64}$

▶️ raízes da equação

• $\small{x'=\dfrac{[-(0)+\sqrt{64}]}{2.(2)}}$

• $\small{x'=\dfrac{[-0+8]}{2.(2)}}$

• $\small{x'=\dfrac{8}{4}}$

• $\small{x'=2}$

• $\small{x"=\dfrac{[-(0)-\sqrt{64}]}{2.(2)}}$

• $\small{x"=\dfrac{[-0-8]}{4}}$

• $\small{x"=-\dfrac{8}{4}}$

• $\small{x"=-2}$

▶️Logo as raízes serão: -2 e 2

• $\red{\large{\boxed{Alternativa\:"b"}}}$