①(-2x-1/3y)²=____②｛（-5+x）（-5-x）｝²=_____③（x+y+z)(x-y-z）=_数学解答

①(-2x-1/3y)²=____②｛（-5+x）（-5-x）｝²=_____③（x+y+z)(x-y-z）=___.④若x²+y²
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人气：166 ℃　时间：2020-05-24 11:21:11

解答

①(-2x-1/3y)²=4x²+4/3x+1/9y²②｛（-5+x）（-5-x）｝²=(25-x²)²=625-50x²+x^4③（x+y+z)(x-y-z）=x²-(y+z)²=x²-y²-z²-2yz