Answer:
[tex]\large\boxed{x=-3-2\sqrt2\ \vee\ x=-2+2\sqrt2}[/tex]
Step-by-step explanation:
[tex]x^2+6x+9=8\\\\x^2+2(x)(3)+3^2=8\qquad\text{use}\ (a+b)^2=a^2+2ab+b^2\\\\(x+3)^2=8\iff x+3=\pm\sqrt8\\\\x+3=\pm\sqrt{4\cdot2}\\\\x+3=\pm\sqrt4\cdot\sqrt2\\\\x+3=\pm2\sqrt2\qquad\text{subtract 3 from both sides}\\\\x=-3-2\sqrt2\ \vee\ x=-2+2\sqrt2[/tex]
