先化简,再求值,(x²-9)/(x²+6x+9)×(3x³+9x²)/(x²-3_数学解答

先化简,再求值,(x²-9)/(x²+6x+9)×(3x³+9x²)/(x²-3x),其中x=-1/3

人气：302 ℃　时间：2020-04-15 00:36:59

解答

原式=(x+3)(x-3)/(x+3)²×3x²(x+3)/x(x-3)
=(x-3)/(x+3)×3x(x+3)/(x-3)
=3x
=3×(-1/3)
=-1