Question

Rationalise the denominator of $\frac{4}{\sqrt{5}}$

• A. $\frac{4\sqrt{5}}{5}$
• B. $\frac{24\sqrt{5}}{5}$
• C. $\frac{14\sqrt{5}}{5}$
• D. $\frac{2\sqrt{5}}{5}$

Answer 1

The correct option is A $\frac{4\sqrt{5}}{5}$

$\frac{4}{\sqrt{5}}=\frac{4}{\sqrt{5}}\times \frac{-\sqrt{5}}{-\sqrt{5}}$

$=\frac{-4\sqrt{5}}{-\sqrt{5^2}}=\frac{4\sqrt{5}}{5}$