Question

Alguém me ajuda por favor? Equação de 2° grau
(x + 2)²= −2x – 5

Answer 1

Resposta:

$(x+2)^2=-2x-5\\x^2+4x+4=-2x-5\\x^2+4x+4+2x+5=0\\x^2+6x+9=0$

a = 1, b = 6, c = 9

$x=\dfrac{-b\pm\sqrt{b^2-4ac}}{2a}\\\\x=\dfrac{-6\pm\sqrt{6^2-4\cdot1\cdot9}}{2\cdot1}\\\\x=\dfrac{-6\pm\sqrt{36-36}}{2}\\\\x=\dfrac{-6\pm\sqrt{0}}{2}\\\\x=\dfrac{-6\pm0}{2}\\\\x=\dfrac{-6}{2}\\\\x=-3$