Classify the following numbers as rational or irrational with justification:
$(i)$ $\sqrt{196}$
$(ii)$ $3 \sqrt{18}$
$(i)$ $\sqrt{196}=14,$ which is a rational number.
$(ii)$ $3 \sqrt{18}=3 \sqrt{9 \times 2}=3 \times 3 \sqrt{2},=9 \sqrt{2},$ which is the product of a rational and an irrational number.
Hence, $3 \sqrt{18}$ is an irrational number.
Value of $\sqrt[4]{(81)^{-2}}$ is
Represent the following numbers on the number line:
$7,7.2, \frac{-3}{2}, \frac{-12}{5}$
Express the following in the form $\frac{p}{q},$ where $p$ and $q$ are integers and $q \neq 0$ :
$0.404040 \ldots$
Express $0.5 \overline{7}$ in the form $\frac{P}{q} ;$ where $p$ and $q$ are integers and $q \neq 0$
If $x=\frac{\sqrt{3}+\sqrt{2}}{\sqrt{3}-\sqrt{2}}$ and $y=\frac{\sqrt{3}-\sqrt{2}}{\sqrt{3}+\sqrt{2}},$ then find the value of $x^{2}+y^{2}$.