化简求值:已知x+4y=-1,xy=5,求(6xy+7y)+【8x-(5xy-y+6x)】的值

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化简求值:已知x+4y=-1,xy=5,求(6xy+7y)+【8x-(5xy-y+6x)】的值化简求值:已知x+4y=-1,xy=5,求(6xy+7y)+【8x-(5xy-y+6x)】的值化简求值:已

化简求值:已知x+4y=-1,xy=5,求(6xy+7y)+【8x-(5xy-y+6x)】的值
化简求值:已知x+4y=-1,xy=5,求(6xy+7y)+【8x-(5xy-y+6x)】的值

化简求值:已知x+4y=-1,xy=5,求(6xy+7y)+【8x-(5xy-y+6x)】的值
原式=6xy+7y+8x-5xy+y-6x
=2x+4y+xy
=2(x+2y)+xy
=-2+5
=3

(6xy+7y)+【8x-(5xy-y+6x)】
=6xy+7y+8x-5xy+y-6x
=xy+2x+8y
=xy+2(x+4y)
∵x+4y=-1,xy=5
∴原式=5-2=3