Question

ORGANIZE E ENCONTRE AS RAÍZES DAS EQUAÇOES A) (2-X)(X+4)=8 B)(3X+4)(3X-4)=0

Answer 1

Explicação passo-a-passo:

Equações do Segundo grau

$\mathtt{ A)~(2 - x)(x + 4)~=~8 }$

$\iff \mathtt{ 2x + \cancel{8}-x^2 - 4x~=~\cancel{8} }$

$\iff \mathtt{ -x^2 - 2x ~=~0 }$

$\iff \mathtt{ -x(x + 2)~=~0 }$

$\iff \mathtt{ \blue{ x~=~0~\vee~x~=~-2} }$

$\mathtt{ B) (3x+4)(3x - 4)~=~0 }$

$\iff \mathtt{ (3x)^2 - 4^2~=~0 }$

$\iff \mathtt{ 9x^2 - 16~=~0 }$

$\iff \mathtt{ x^2~=~\dfrac{16}{9} }$

$\iff \mathtt{ x~=~\pm \sqrt{ \dfrac{16}{9} }~=~\pink{\pm \dfrac{4}{3}} }$

Espero ter ajudado bastante!)