<h3>
Answer:</h3>
The real solutions are -5, -4, 4, 5. There are no complex solutions.
<h3>
Step-by-step explanation:</h3>
The equation ...
... x^4 -41x^2 +400 = 0
can be factored as ...
... (x^2 -16)(x^2 -25) = 0
... (x -4)(x +4)(x -5)(x +5) = 0
So, all roots are real and are ...
... x ∈ {-5, -4, 4, 5}
_____
These are the values of x that make the factors zero.