(x+1/x^2+1)÷(（x+1)^3/x^4-1 )-(x-3/x+1)其中x=根号下3+1

[x+1/x^2+1)]÷[（x+1)^3/x^4-1]-(x-3/x+1)
=(x+1)(x^4-1)/[(x^2+1)(x+1)^3]-(x-3)/(x+1)
=(x+1)(x^2+1)(x+1)(x-1)/[(x^2+1)(x+1)^3]-(x-3)/(x+1)
=(x-1)/(x+1)-(x-3)/(x+1)
==(x-1-x+3)/(x+1)
=2/(x+1)
=2/(√3+1+1)
=2/(2+√3)
=2(2-√3)/(2+√3)(2-√3)
=(4-2√3)/(4-3)
=4-2√3

是算结果的么 简化之后是2/(X+1)

先化简，再求值
x+1/x^2+1)÷（x+1）^3/x^4-1)-(x-3/x+1)
其中 x=根号3+1
原式=(X+1)(X^4-1)/[(X方+1)(X+1)^3]-(X-3)/(X+1)
=(X方+1)(X+1)(X-1)/[(X方+1)(X+1)方]-(X-3)/(X+1)
=(X-1)/(X+1)-(X-3)/(X+1)
=2/(X+1)
把X=根号3+1代入得
原式=2/(根号3+2)
=2(2-根号3)