[(x-2y)²+(3x-2y)(3x+2y)]÷(-5x) (a-2b+3)(-a-2b-3).

问题描述:

[(x-2y)²+(3x-2y)(3x+2y)]÷(-5x) (a-2b+3)(-a-2b-3).
1个回答 分类:数学 2014-11-23

问题解答:

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[(x-2y)²+(3x-2y)(3x+2y)]÷(-5x)
=(x²-4xy+4y²+9x²-4y²)÷(-5x)
=(10x²-4xy)÷(-5x)
=-2x +4y/5
(a-2b+3)(-a-2b-3).
=-(a-2b+3)(a+2b+3)
=-[(a+3)-2b][(a+3)+2b]
=-[(a+3)²-4b²]
=-(a²+6a+9-4b²)
=-a²-6a-9+4b²
 
 
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