(x-1)²+(x+3)(x-3)+(x-3)(x-1),其中x²-2x=2。先化简再求值,要过程
(x-1)²+(x+3)(x-3)+(x-3)(x-1),其中x²-2x=2。先化简再求值,要过程谢谢!...
(x-1)²+(x+3)(x-3)+(x-3)(x-1),其中x²-2x=2。先化简再求值,要过程谢谢!
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2014-11-30
展开全部
2(x-1)^2-(x+3)(x-3)-(x-3)(x-1),
=2(x-1)^2-(x-3)(x-1)-(x+3)(x-3),
=(x-1)[2(x-1)-(x-3)]-(x+3)(x-3)
=(x-1)[2x-2-x+3]-(x+3)(x-3)
=(x-1)(x+1)-(x+3)(x-3)
=x^2-1-(x^2-9)
=x^2-1-x^2+9
=8
来自网络
=2(x-1)^2-(x-3)(x-1)-(x+3)(x-3),
=(x-1)[2(x-1)-(x-3)]-(x+3)(x-3)
=(x-1)[2x-2-x+3]-(x+3)(x-3)
=(x-1)(x+1)-(x+3)(x-3)
=x^2-1-(x^2-9)
=x^2-1-x^2+9
=8
来自网络
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用完全平方公式来解,谢谢
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