（X分之X-1减X+1分之X-2）除以 X平方+2X+1分之X平方-X,其中X平方-X-1=0
=[((x-1)(x+1)-x(x-1)]/x(x+1)÷(x²-x-1+1)/(x+1)²
=(x²-1-x²+x)/x(x+1)*[(x+1)²]
=(x-1)(x+1)/x
=(x²-1)/x
=(x²-x-1+x)/x
=x/x
=1