Question 54577
Assume you mean:
:
{{{(6-SqRt(20))/2}}}
:
Find the largest square which is a factor of 20, it's 4, rewrite it:
:
{{{(6-SqRt(4*5))/2}}}
:
:
Extract the square root of 4 and you have:
:
{{{(6 - 2*SqRt(5))/2}}}
:
:
Note that you can divide the 2 into 2 and into 6, leaving you with
:
{{{3 - SqRt(5)}}}