Question 181639
Rationalize the denominator. 
5/6 -(square root of 5) 
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{{{5/(6-sqrt(5))}}}
The way to do these is to multiply NUM and DEN by the conjugate of the DEN.
The conjugate of {{{6-sqrt(5))}}} is {{{6+sqrt(5))}}}
The sign is different between the 2 terms, called the conjugate.
={{{5(6+sqrt(5))/(6-sqrt(5))*(6+sqrt(5))}}}
={{{(30+5sqrt(5))/(36-5)}}}
={{{(30+5sqrt(5))/31}}}