Introduce new variable y = . Then = x.
Then your equation takes the form
= ====> (Multiply both sides by 4) ====>
= ====>
= 0 ====> (apply the quadratic formula) ====>
= = = .
1) = = = 6 ====> = = 36;
2) = = = ====> = = .
Check each root. You will see that x = 36 is valid solution, while x = is EXTRANEOUS.
Answer. The solution (and the only solution) is x = 36.
Illustration:
Plot y = (the left side of the original equation; red line) and y = x (the right side; green).