Answer
$...=5^{\frac{1}{2}+\frac{1}{2}+\frac{1}{2}+\frac{1}{2}}=5^{\frac{1}{2}\cdot 4}=5^{2}$
Work Step by Step
$(5^{1/2})^{4}=5^{1/2}\cdot 5^{1/2}\cdot 5^{1/2}\cdot 5^{1/2}=5^{\frac{1}{2}+\frac{1}{2}+\frac{1}{2}+\frac{1}{2}}=5^{\frac{1}{2}\cdot 4}=5^{2}$
