>>165
6 / (3 + √6 - √3) =6 (3 -(√6 - √3)) / (3 + √6 - √3)(3 -( √6 - √3))
=6(3 -√6 +√3)/{9-(√6 - √3)^2}
=6(3 -√6 +√3)/2√18=(3 -√6 +√3)/√2=(3√2 - 2√3 + √6) / 2