To rewrite the expression \( (19^4)^{10} \) as a single power, you can use the property of exponents that states \( (a^m)^n = a^{m \cdot n} \).
Applying this to your expression:
\[ (19^4)^{10} = 19^{4 \cdot 10} = 19^{40} \]
So, the expression rewritten as a single power is \( 19^{40} \).