来自李海阳的问题
化简求值:[(x+2y)2-(x+y)(3x-y)-5y2]÷2x,其中x=-2,y=12.
化简求值:[(x+2y)2-(x+y)(3x-y)-5y2]÷2x,其中x=-2,y=12.
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2020-06-18 14:40
化简求值:[(x+2y)2-(x+y)(3x-y)-5y2]÷2x,其中x=-2,y=12.
化简求值:[(x+2y)2-(x+y)(3x-y)-5y2]÷2x,其中x=-2,y=12.
[(x+2y)2-(x+y)(3x-y)-5y2]÷2x
=(x2+4xy+4y2-3x2-2xy+y2-5y2)÷2x
=(-2x2+2xy)÷2x
=y-x,
当x=-2,y=12