Question 1064735
It sounds like your teacher wants you to rationalize the denominator. To do so, multiply top and bottom of the fraction by {{{sqrt(3)}}} to get...



{{{(sqrt(5))/(sqrt(3))=(sqrt(5)*sqrt(3))/(sqrt(3)*sqrt(3))}}}



{{{(sqrt(5))/(sqrt(3))=(sqrt(5*3))/(sqrt(3*3))}}}



{{{(sqrt(5))/(sqrt(3))=(sqrt(15))/(sqrt(9))}}}



{{{(sqrt(5))/(sqrt(3))=(sqrt(15))/(3)}}}