Answer:
(-√(6-√26) < x < √(6-√26)) ∪ (x < -√(6 +√26)) ∪ (√(6 +√26) < x)
Explanation:
Using x^2 = z, the equation can be rewritten as ...
z^2 -12z +10 > 0
(z -6)^2 -26 > 0
|z -6| > √26
This resolves to two equations.
This one ...
x^2 -6 < -√26 . . . . substitute x^2 for z
|x| < √(6-√26) . . . . add 6, take the square root; use √a^2 = |a|
-√(6-√26) < x < √(6-√26)
__
and this one ...
x^2 -6 > √26
|x| > √(6 +√26)
x < -√(6 +√26) ∪ √(6 +√26) < x