Question 241275
If (x-1/x)=5, then square both sides and get this:

{{{(x-1/x)^2=25}}}
{{{x^2 -2*x*(1/x)+1/x^2=25}}}
{{{x^2-2+1/x^2=25}}}

Add +2 to each side:
{{{x^2+1/x^2=27}}}


Dr. Robert J. Rapalje, Retired
Seminole State College of Florida
Altamonte Springs Campus