化简求值已知[x-(x/x+1)]*(x+1/x^2+3x+2)除以(x^2-2x/x^2-4),其中x=-1/2_数学解答

化简求值已知[x-(x/x+1)]*(x+1/x^2+3x+2)除以(x^2-2x/x^2-4),其中x=-1/2

人气：145 ℃　时间：2020-01-27 09:03:39

解答

=(x²+x-x)/(x+1)×(x+1)/(x+2)(x+1)×(x+2)(x-2)/x(x-2)
=x²/(x+1)×(x+1)/(x+2)(x+1)×(x+2)(x-2)/x(x-2)
=x/(x+1)
x=-1/2时
原式=-1/2/(-1/2+1)
=-1