What is the value of $(2.3+1.7)^{2}-(2.3-1.7)^{2} ?$

$\frac{1}{\left(2 \frac{1}{3}\right)}+\frac{1}{\left(1 \frac{3}{4}\right)}$ is equal to

If $a+b+c=6, a^{2}+b^{2}+c^{2}=14$ and $a^{3}+b^{3}+c^{3}=36,$ then the value of $abc$ is

If $(a+\frac{1}{a})^{2}=3,$ then $a^{3}+\frac{1}{a^{3}}=?$

$\left\{7 \frac{1}{2} + \frac{1}{2} \div \frac{1}{2} \text{ of } \frac{1}{4} - \frac{2}{5} \times 2 \frac{1}{3} \div 1 \frac{7}{8} \text{ of } \left(1 \frac{2}{5} - 1 \frac{1}{3}\right)\right\} = ?$

If $x * y = x^{2} + y^{2} - xy$,then the value of $9 * 11$ is