Simplify 2/sqrt(5)

[math_celebrity]

To do this, we need rationalize the denominator. This means get rid of the radical:

Multiply top and bottom by sqrt(5)
2sqrt(5)/sqrt(5) * sqrt(5)

sqrt(5) * sqrt(5) = sqrt(25) so we have:
2sqrt(5)/sqrt(25)

sqrt(25) = 5, so we have:
2sqrt(5)/5