Originally Posted by
earboth $\displaystyle \sqrt{2^{109}} \cdot \sqrt{x^{306}} \cdot \sqrt{x^{11}} = 2^{\frac{109}2} \cdot x^{\frac{306}2} \cdot x^{\frac{11}2}$
Use the law of powers:
$\displaystyle a^x \cdot a^y = a^{x+y}$
Btw: $\displaystyle 2^{\frac{109}2} = 2^{54+\frac12}$