2[(620)² + (580)²] - (620 + 580)² = ?

Find the square root of 0.000625 and express it as a fraction.

$$\sqrt{0.25} - \sqrt[3]{0.008} + \sqrt{0.36} + \sqrt[4]{0.0256}$$ = ?

​$$\sqrt{12.25} =$$​​

$$\frac{1}{9 + \sqrt{6}} + \frac{1}{9 - \sqrt{6}}$$ = ?

​$$\sqrt{2.25 × 0.01}$$ = ?

2[(620)² + (580)²] - (620 + 580)² = ?

​$$\sqrt{56.25} + \sqrt{30.25} - \sqrt{12.25} - \sqrt{20.25}$$ = ?

If $$\sqrt{506.25} = 22.5$$​, then what is the value of  $$\sqrt{0.00050625}$$​?

Simplify : $$\frac{\sqrt[3]{2744}}{\sqrt[4]{256}} \times \frac{2}{42} \times 72$$​

Find the least number that must be added to 5600 to make it a perfect square.