问题
填空题
计算:42009×(-0.25)2008-1=______.
答案
42009×(-0.25)2008-1,
=4×42008×(-
)2008-1,1 4
=4×[4×(-
)]2008-1,1 4
=4×(-1)2008-1,
=4-1,
=3.
计算:42009×(-0.25)2008-1=______.
42009×(-0.25)2008-1,
=4×42008×(-
)2008-1,1 4
=4×[4×(-
)]2008-1,1 4
=4×(-1)2008-1,
=4-1,
=3.