Fill in the blank to make the following statement true:
$(729)^{\frac{1}{3}} = \ldots$

Rationalise the denominator of the following:
$\frac{2}{3 \sqrt{3}}$

Let $x$ and $y$ be rational and irrational numbers,respectively. Is $x+y$ necessarily an irrational number? Give an example in support of your answer.

Represent $\sqrt{4.5}$ geometrically on the number line.

The value of $(256)^{0.16} \times (256)^{0.09}$ is

If $x = 3 + 2\sqrt{2}$,then find the value of $x^{2} + \frac{1}{x^{2}}$ and $x^{3} + \frac{1}{x^{3}}$.