X²-2X-2=0
X=[2±√(4+8)]/2=1±√3
则正数根为X=1+√3
(X²-1)/(X²+X)÷[X-(2X-1)/X]
=(X+1)(X-1)/X(X+1)÷(X²-2X+1)/X
=(X-1)/X÷(X-1)²/X
=(X-1)/X×X/(X-1)²
=1/(X-1)
=1/(1+√3-1)
=√3/3
X²-2X-2=0
X=[2±√(4+8)]/2=1±√3
则正数根为X=1+√3
(X²-1)/(X²+X)÷[X-(2X-1)/X]
=(X+1)(X-1)/X(X+1)÷(X²-2X+1)/X
=(X-1)/X÷(X-1)²/X
=(X-1)/X×X/(X-1)²
=1/(X-1)
=1/(1+√3-1)
=√3/3