Rationalise the denominator of the fraction 3/sqrt(5)

In order to rationalise the denominator we need to get rid of the surd (square-root) on the bottom of the fraction.

To do this, we can multiply the denominator by sqrt(5).

But we must notice that to keep the fraction the same, we must multiply the denominator and numerator by the same number.

Therefore, by multiplying the top and bottom of the fraction by sqrt(5), we get 3*sqrt(5)/5 as our rationalised fraction.