先化简,在求值 1/x+1-x+3/x²-1*x²-2x+1/x²+4x+3,其中x=2_数学解答

先化简,在求值 1/x+1-x+3/x²-1*x²-2x+1/x²+4x+3,其中x=2

人气：436 ℃　时间：2020-01-26 01:51:01

解答

原式=1/(x+1)-(x+3)/(x+1)(x-1)*(x-1)²/(x+3)(x+1)
=1/(x+1)-(x-1)/(x+1)²
=(x+1-x+1)/(x+1)²
=2/(x+1)²
=2/9

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