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下列运算正确的是( ) A.3a-2a=1 B.(a-3)2=a2+6a+9 C...
下列运算正确的是( )
A.3a-2a=1
B.(a-3)2=a2+6a+9
C.a2•a3=a6
D.(a+2)•(a2-2a)=a3-4a
考点分析:
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下列计算正确的是( )
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=6
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B.
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=4
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÷
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=3
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=-3
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