Question

Encontre as raízes da equação: x2 – 4x – 5 = 0

Answer 1

2x-4x=5
-2x=5
x=5/-2
x=-2,5

Answer 2

$x^2-4x-5=0$

Coeficientes: a = 1, b = -4 e c = -5.

$\Delta=b^2-4ac\\\Delta=(-4)^2-4.1.(-5)\\\Delta=16+20\\\Delta=36$

$x=\frac{-b+-\sqrt{\Delta}}{2a}\\\\x=\frac{-(-4)+-\sqrt{36}}{2.1}\\\\x=\frac{4+-6}{2}\\\\x'=\frac{4+6}{2}=5\\\\x"=\frac{4-6}{2}=-\frac{2}{2}=-1$


Espero ter ajudado.
Bons estudos! :)