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3 |
∴三个非负数的和为0,必须都为0,即a+2=0,b+1=0,c-
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解得:a=-2,b=-1,c=
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5abc-{2a2b-[3abc-(4ab2-a2b)]}
=5abc-{2a2b-[3abc-4ab2+a2b]}
=5abc-{2a2b-3abc+4ab2-a2b}
=5abc-2a2b+3abc-4ab2+a2b
=8abc-a2b-4ab2,
当a=-2,b=-1,c=
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原式=8×(-2)×(-1)×
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=
16 |
3 |
=17
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3 |
1 |
3 |
1 |
3 |
1 |
3 |
1 |
3 |
1 |
3 |
1 |
3 |
16 |
3 |
1 |
3 |