5. To make the equation
$$
x^{4}+(m-4) x^{2}+2(1-m)=0
$$

have exactly one real root that is not less than 2, the range of values for $m$ is $\qquad$.
Let $x^{2}=y$. Then the original equation becomes
$$
y^{2}+(m-4) y+2(1-m)=0 \text {. }
$$

By the problem statement, this equation has exactly one real root that is not less than 4.
Answer: $m \leqslant-1$.