先化简,再求值:(x-1⼀x)-(x-2⼀x+1)除以2x^2-x⼀x^2+2x+1,其中x满足x^2-x-1=0

2024-11-26 22:42:38
推荐回答(2个)
回答1:

[(x-1)/x-(x-2)/(x+1)]÷(2x²-x)/x²+2x+1
=[(x-1)(x+1)-x(x-2)]/x(x+1)×(x+1)²/(2x²-x)
=(-x²+2x-1)/x×(x+1)/x(2x-1)
=(-x²+2x-1)(x+1)/x²(2x-1)
∵x²-x-1=0 ∴x²=x+1
∴(-x²+2x-1)(x+1)/x²(2x-1)
=(-x-1+2x-1)(x+1)/(x+1)(2x-1)
=(x-2)/(2x-1)

回答2:

(x-2)/(2x-1)