### Square and Square Roots

goals
Divide:
$21\sqrt {384}\div 8\sqrt {96}$
Evaluate: [$\displaystyle\sqrt{\left (5\, +\, 2\frac{21}{25}\right )\, \times\, \frac{0.169}{1.6}}$] $\times 100$
Which one of the following cannot be the square of a natural number ?
Find a number that is divisible by 15, 18, and 25 and is a perfect square
On simplification the product of given expression $\left (x - \dfrac {1}{x}\right )\left (x + \dfrac {1}{x}\right )\left (x^{2} + \dfrac {1}{x^{2}}\right )$ is ________.