〔（x-1）/x—（x-2）/x+1 〕÷〔2x²-x/x²+2x+1〕=[(x-1)(x+1)-x(x-2)]/x(x+1)÷x(2x-1)/(x+1)²=(x²-1-x²+2x)/x(x+1)×(x+1)²/x(2x-1)=x+1/x²∵x²-x-1=0x²=-(x+1)∴〔（x-1）/x—（x-2）/x+1 〕÷〔2x²-x/x²+2x+1〕=(x+1)/-(x+1)=-1
化简的（x+1）/x
gb
