Question

Resolva as equaçôes
De 2° grau com uma incógnita
a) x² - 1 = 0

b) 3x² - 27 = 0

c) 5x² - 45x = 0

Answer 1

Resposta:

OLÁ

VAMOS A SUA PERGUNTA:⇒⇒

A:)→

$x^{2} -1=0$

$x=\dfrac{0\pm\sqrt{0^2-4(-1)} }{2}$

$x=\dfrac{0\pm\sqrt{-4(-1)} }{2}$

$x=\dfrac{0\pm\sqrt{4} }{2}$

$x=\dfrac{0\pm2 }{2}$

$x=1$

$x=-1$

$\boxed{\bold{\displaystyle{\clubsuit\ \spadesuit\ \maltese\ x=1}}}\ \checkmark\\\\\boxed{\bold{\displaystyle{\clubsuit\ \spadesuit\ \maltese\ x=-1}}}\ \checkmark$←↑ RESPOSTA.

B:)→

$3x^2-27=0$

$x=\dfrac{0\pm\sqrt{0^2-4\times3(-27)} }{2\times3}$

$x=\dfrac{0\pm\sqrt{-4\times3(-27)} }{2\times3}$

$x=\dfrac{0\pm\sqrt{-12(-27)} }{2\times3}$

$x=\dfrac{0\pm\sqrt{324} }{2\times3}$

$x=\dfrac{0\pm18 }{2\times3}$

$x=\dfrac{0\pm18 }{6}$

$x=3$

$x=-3$

$\boxed{\bold{\displaystyle{\clubsuit\ \spadesuit\ \maltese\ x=3 }}}\ \checkmark\\\\\boxed{\bold{\displaystyle{\clubsuit\ \spadesuit\ \maltese\ x=-3}}}\ \checkmark$← ↑RESPOSTA.

C:)→

$5x^2-45x=0$

$x=\dfrac{-(-45)\pm\sqrt{(-45)^2} }{2\times5}$

$x=\dfrac{-(-45)\pm45 }{2\times5}$

$x=\dfrac{45\pm45 }{10}$

$x=\dfrac{90}{10}$

$x=9$

$x=\dfrac{0}{10}$

$x=0$

$\boxed{\bold{\displaystyle{\clubsuit\ \spadesuit\ \maltese\ x=9 }}}\ \checkmark\\\\\boxed{\bold{\displaystyle{\clubsuit\ \spadesuit\ \maltese\ x=0}}}\ \checkmark$←↑ RESPOSTA.

Explicação passo-a-passo:

ESPERO TER AJUDADO