7. What is the product of \( 9 \sqrt{8} \) and \( 6 \sqrt{20} \) in simplest tadficall form?

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. \( \log \left(\frac{x^{4} y^{17}}{z^{2}}\right)=\square \)

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

The half-life of radium is 1690 years. If 60 grams are present now, how much will be present in 430 years? \( \square \) grams (Do not round until the final answer. Then round to the nearest thousandth as needed.)

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.