Question 1131441
multiply by the denominator, since sqrt(5)*sqrt(5)=5.  Multiply by whatever it takes to remove the radical.
1/sqrt(5) multiplied by sqrt(5)/sqrt(5)=sqrt(5)/5

Here, multiply by the conjugate, 2- sqrt(3), numerator and denominator.
The numerator becomes 2(2-sqrt(3)), and the denominator becomes (2+ sqrt(3))*(2- sqrt(3))
which becomes 4-2 sqrt(3)+2sqrt(3)-sqrt(3)(sqrt(3).  the middle two terms equal 0 and the denominator becomes 4-3, or 1
The answer is 5*(2- sqrt(3))