How do I solve this equation?

Answer: x=2, x=-2, x=0
Step-by-step explanation:
You would start by doing PEMDAS first which would settle everything down to x^4+8x^2+48 = 12x^2 +48
Subtract 48 from both sides which would give you x^4 +8x^2 =12x^2
Subtract 12x^2 from both sides and simplify it down to x^4 - 4x^2 = 0 then change the X's to U.
Rest is explained in the attachment