先化简,在求值：（a-2/a²+2a - a-1/a²+4a+4)除于a-4/a+2,其中a满足：a2+2a-1=0

先化简,在求值：（a-2/a²+2a - a-1/a²+4a+4)除于a-4/a+2,其中a满足：a2+2a-1=0
先化简,在求值：（a-2/a²+2a - a-1/a²+4a+4)除于a-4/a+2,其中a满足：a2+2a-1=0

先化简,在求值：（a-2/a²+2a - a-1/a²+4a+4)除于a-4/a+2,其中a满足：a2+2a-1=0

a²+2a-1=0
则：
[（a-2)/a(a+2) - (a-1)/(a+2)²] ÷a-4/a+2
=[（a-2)/a(a+2) - (a-1)/(a+2)²] (a+2)/(a-4)
=[（a-2)/a - (a-1)/(a+2)]/(a-4)
=[（a²-4) - (a²-a)]/[a(a+2)(a-4)]
=(a-4)/[a(a+2)(a-4)]
=1/[a²+2a]
=1/[a²+2a-1+1]
=1