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用简便方法计算.(1)(-14)4005×162003=______;(2)318×(-19
问题详情
用简便方法计算.
(1)(-
(2)318×(-
(3)(0.5×3
(4)0.259×220×259×643=______.
参考答案
(1)(-14)4005×162003
=(-14)4005×(42)2003
=(-14)4005×44006
=(-14)4005×44005×4
=[(-14)×4]4005×4
=(-1)×4
=-4;
(2)318×(-19)8
=318×[-(13)2]8
=318×(13)16
=316+2×(13)16
=(3×13)16×32
=9;
(3)(0.5×323)199?(-2×311)200
=(0.5×113)199?(-2×311)200
=[0.5×113×(-2)×311]199×(-2×311)
=611;
(4)0.259×220×259×643
=0.259×643×220×259
=0.259×(43)3×410×259
=(0.25×4)9×(4×25)9×4
=4×1018.
考点:方法