已知x-y=-3,xy=2则3x-5y-(x-3y-4xy)是多少

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已知x-y=-3,xy=2则3x-5y-(x-3y-4xy)是多少已知x-y=-3,xy=2则3x-5y-(x-3y-4xy)是多少已知x-y=-3,xy=2则3x-5y-(x-3y-4xy)是多少3

已知x-y=-3,xy=2则3x-5y-(x-3y-4xy)是多少
已知x-y=-3,xy=2则3x-5y-(x-3y-4xy)是多少

已知x-y=-3,xy=2则3x-5y-(x-3y-4xy)是多少
3x-5y-(x-3y-4xy)
=3x-5y-x+3y+4xy
=2x-2y+4xy
=2(x-y)+4xy
=2×(-3)+4×2
=-6+8
=2

2

3x-5y-(x-3y-4xy)=3x-5y-x+3y+4xy=2x-2y+4xy=2(x-y)+4xy=-6+8=2

2

3x-5y-(x-3y-4xy)
=3x-5y-x+3y+4xy
=2x-2y+4xy
=2(x-y)+4xy
=2×(-3)+4×2
=-6+8
=2

2