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: