问题 填空题

计算:42009×(-0.25)2008-1=______.

答案

42009×(-0.25)2008-1,

=4×42008×(-

1
4
2008-1,

=4×[4×(-

1
4
)]2008-1,

=4×(-1)2008-1,

=4-1,

=3.

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