Simplify the nth root, if possible. Select "Not a real number" if applicable. \[ \sqrt[3]{-216}=\square \quad \begin{array}{cc}\begin{array}{c}\text { Not a } \\ \text { real } \\ \text { number }\end{array} & \frac{\square}{\square}\end{array} \]

Simplify \( \frac{8}{\sqrt{6}+2} \)

Julie swam, biked, and ran in a 22.2 mile triathlon. She completed the race in 2.15 hours. The function \( m=13.8 \mathrm{~h} \) represents the miles \( m \) Julie biked in \( h \) hours. Was her average speed biking less than or greater than her average speed for the entire race? Justify your answer. Round to the nearest tenth if necessary.

Simplify the logarithmic expression: \( \text{\log}_{2}(8) + \text{\log}_{2}(4) \)

11. Вычислите: \( \frac{10^{7}}{5^{6} \cdot 2^{7}} \)

Write expression \( \log \left(\frac{x^{4} y^{17}}{z^{2}}\right) \) as a sum or difference of logarithms with no exponents. Simplify your answer completely. \( \log \left(\frac{x^{4} y^{17}}{z^{2}}\right)=\square \)