(x^2+5)/(2x)=5
x^2+5=2x*5
x^2+5=10x
x^2-10x+5=0
"This is a quadratic function .We should find the roots of the function."
"if "ax^2+bx+c=0
Delta=sqrt (b^2-4ac)
"Where "a=1" , "b=-10" , "c=5
Delta=sqrt((-10)^2-4*1*5)=sqrt(100-20)=+-sqrt(80)
x_1=(-b-Delta)/(2a)=(10-sqrt 80)/(2*1)=(10-4sqrt5)/2=5-2sqrt5
x_1=(-b+Delta)/(2a)=(10+sqrt 80)/(2*1)=(10+4sqrt5)/2=5+2sqrt5