Question 668156
Starting with
{{{3/(9-sqrt(2))}}}
...
{{{(3/(9-sqrt(2)))((9+sqrt(2))/(9+sqrt(2))) = (3(9+sqrt(2)))/((9-sqrt(2))(9+sqrt(2)))}}}
...
The denominator
{{{(9-sqrt(2))*(9+sqrt(2)) = 81 + cross(9sqrt(2)) - cross(9sqrt(2)) - sqrt(2)^2}}}
same as 
81 - 2 = 79
...
The numerator
{{{3(9+sqrt(2)) = 27 + 3sqrt(2)}}}
...
Result
{{{highlight_green((27+3sqrt(2))/79)}}}
.....
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