[tex]x = -4 \pm \sqrt{19}[/tex]
Step-by-step explanation:
Let us put 3 on the right side and rewrite the equation as
[tex]x^2 + 8x = 3[/tex]
By putting 16 on both sides, our equation becomes
[tex]x^2 + 8x + 16 = 3 + 16 = 19[/tex]
[tex]\Rightarrow (x + 4)^2 = 19[/tex]
Taking the square root of the equation, we get
[tex]x + 4 = \pm \sqrt{19}[/tex]
Finally, solving for x,
[tex]x = -4 \pm \sqrt{19}[/tex]