Simplify:
$64^{-\frac{1}{3}} + 64^{\frac{1}{3}} - 64^{\frac{2}{3}}$
State whether the following statements are true or false? Justify your answer.
$(i)$ The square of an irrational number is always rational.
$(ii)$ $\frac{\sqrt{12}}{\sqrt{3}}$ is not a rational number as $\sqrt{12}$ and $\sqrt{3}$ are not integers.
Simplify the following:
$\sqrt[4]{81}-8 \sqrt[3]{216}+15 \sqrt[5]{32}+\sqrt{225}$
$2 \sqrt{3}+\sqrt{3}$ is equal to
Multiply $3 \sqrt{7}$ and $5 \sqrt{7}$.
Convert following rational numbers in decimal form and state the kind of its decimal expansion
$\frac{25}{8}$