We can evaluate the given expression by substituting the values of `tan 60°` and `tan 30°`. The value of `tan 60°` is `sqrt(3)`, and the value of `tan 30°` is `1/sqrt(3)`. Substituting these values into the given expression, we get:

\(\frac{tan 60^o - tan 30^o}{tan 60^o + tan 30^o} = \frac{\sqrt{3} - \frac{1}{\sqrt{3}}}{\sqrt{3} + \frac{1}{\sqrt{3}}} = \frac{\sqrt{3} - \frac{1}{\sqrt{3}}}{\sqrt{3} + \frac{1}{\sqrt{3}}} \frac{\sqrt{3}}{\sqrt{3}} = \frac{3 - 1}{3 + 1} = \frac{2}{4} = \frac{1}{2}\)

So, the value of the given expression is 1/2.