WILL GIVE BRAINLIEST!! NEED HELP PRETTY QUICKLY!! Use U-Substitution to solve the following polynomial. Compare the imaginary roots to the Code Breaker Guide to determine the seventh piece of the code.

4x4 + 2x2 – 12 = 0
Let u =
Equation using u:
Solve for u:
Solve for x:
Imaginary Roots:
Real Roots:
Code Piece:


Thank you!!!!