Question 932551
{{{ (-4)/(sqrt ( 7 )+sqrt ( 5 )) = ((-4)/(sqrt ( 7 )+sqrt ( 5 )))((sqrt(7)-sqrt(5))/(sqrt(7)-sqrt(5)))}}}
{{{ (-4)/(sqrt ( 7 )+sqrt ( 5 )) = ((-4sqrt(7)+4sqrt(5))/(7-sqrt(35)+sqrt(35)-5))}}}
{{{ (-4)/(sqrt ( 7 )+sqrt ( 5 )) = ((-4sqrt(7)+4sqrt(5))/(2))}}}
{{{ (-4)/(sqrt ( 7 )+sqrt ( 5 )) = -2sqrt(7)+2sqrt(5)}}}