Respuesta :

Steps:

[tex]x=\frac{-8+\sqrt{8^2-4\cdot \:1\cdot \:20}}{2\cdot \:1}: -4+2i[/tex]

[tex]x=\frac{-8-\sqrt{8^2-4\cdot \:1\cdot \:20}}{2\cdot \:1} -4-2i[/tex]

=\frac{-8-\sqrt{16}i}{2\cdot \:1}[tex]=-8-\sqrt{16}i[/tex]

[tex]=\frac{-8-\sqrt{16}i}{2}[/tex]

[tex]=\frac{-8-4i}{2}[/tex]

[tex]=-2\left(2+i\right)[/tex]

[tex]=-4-2i[/tex]

[tex]x=-4+2i,\:x=-4-2i[/tex]

Answer:you can use the quadratic formula but if you have to factor do the following:

x^2+8x+20=0

add -4 to both sides of the equation to complete the square

x^2+8x+20+(-4)=0+(-4)

x^2+8x+16=-4

(x+4)^2=-4

take the square root of both sides

x+4=+sqrt(-4)

x+4=+sqrt[(4)(-1)]

x+4=+2sqrt(-1) where sqrt(-1)=i, a complex number

x+4=+2i

x=-4+2i

x=-4+2i and x=-4-2i

you would get the same answer using the quadratic formula

Step-by-step explanation: