已知x+y=-2,xy=3,求2(xy-3x)-3(2y-xy)的值

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已知x+y=-2,xy=3,求2(xy-3x)-3(2y-xy)的值
已知x+y=-2,xy=3,求2(xy-3x)-3(2y-xy)的值

已知x+y=-2,xy=3,求2(xy-3x)-3(2y-xy)的值
原式=2xy-6x-6y+3xy
=5xy-6(x+y)
=5×3-6×(-2)
=27

2(xy-3x)-3(2y-xy)
=2xy-6x-6y+3xy
=5xy-6(x+y)
=5×3-6×﹙-2﹚
=27

=5xy-6(x+y)=27

2(xy-3x)-3(2y-xy)=5xy-6(x+y)=27

2(xy-3x)-3(2y-xy)
=2xy-6x-6y+3xy
=5xy-6(x+y)
=5*3-6*(-2)
=27

原式为2(3-3x)-3(2y-3)=6-6x-6y+9=15-6(x+y)=15+12=27