Question 358636
{{{ (sqrt(x) - sqrt(y))/(sqrt(x) + sqrt(y) ) =(sqrt(x) - sqrt(y))/(sqrt(x) + sqrt(y) ) *(sqrt(x) - sqrt(y))/(sqrt(x) - sqrt(y) ) }}}
{{{ (sqrt(x) - sqrt(y))/(sqrt(x) + sqrt(y) ) =(x-sqrt(xy)-sqrt(xy)+y)/(x-sqrt(xy)+sqrt(xy)-y) }}}
{{{ (sqrt(x) - sqrt(y))/(sqrt(x) + sqrt(y) ) =(x-2sqrt(xy)+y)/(x-y) }}}