Question

数学题，麻烦学霸了！

先化简,再求值:[1-1/(a+1)](a²+2a+1)，其中a=√3-1

Answer 1

原式=(a+1-1)/(a+1)×(a+1)²
=a/(a+1)
=(√3-1)/(√3-1+1)
=(3-√3)/3

Answer 2

[1-1/(a+1)](a²+2a+1)
=[a/(a+1)] (a+1)²
=a/(a+1)

由a=√3-1得原式=1-√3/3