Answer:
[tex]\large\boxed{x=-1\ \vee\ x=1}[/tex]
Step-by-step explanation:
[tex]8x^2+4=12\qquad\text{subtract 4 from both sides}\\\\8x^2+4-4=12-4\\\\8x^2=8\qquad\text{divide both sides by 8}\\\\\dfrac{8x^2}{8}=\dfrac{8}{8}\\\\x^2=1\to x=\pm\sqrt1\\\\x=-1\ \vee\ x=1[/tex]
