Question

8- Resolva a inequação (x + 4)(x – 4) <0.
a) ( ) - 4<x<-4
b) ( ) - 4<x<4
c) ( ) - 4<x< 0
d) ( ) 0<x<-4
e) ( ) 4<x<4​

Answer 1

Resposta: b) -4<x<4

Explicação passo-a-passo:

Veja a imagem

Answer 2

(x + 4)(x – 4) <0.

$\left(x+4\right)\left(x-4\right):\quad x^2-16\\\\x^2-16<0\\\\x^2-16+16<0+16\\\\x^2<16$

$\mathrm{Para\:}u^n\:<\:a\mathrm{,\:se\:}n\:\mathrm{e\:par}\mathrm{\:entao\:}-\sqrt[n]{a}\:<\:u\:<\:\sqrt[n]{a}$

$-\sqrt{16}<x<\sqrt{16}\\\\\sqrt{16}=4\\\\-4<x<4$

RS:ALTERNATIVA (B)

Espero Ter Ajudado