问题
解答题
下面各题,怎样算简便就怎样算.
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答案
①1080+270÷18-864
=1080+15-864,
=231;
②7.54+
+2.46+12 7 16 7
=(7.54+2.46)+(
+12 7
),16 7
=10+4,
=14;
③(2.4-
)÷0.625+23 20 4 5
=(2.4-1.15)÷0.625+0.8,
=1.25÷0.625+0.8,
=2+0.8,
=2.8;
④2.5×12.5×40×0.8
=(2.5×40)×(12.5×0.8),
=100+10,
=110;
⑤98.9×99+98.9
=(99+1)×98.9,
=100×98.9,
=9890;
⑥40.5÷
×[(1-1 4
)×1.2]1 4
=40.5÷
×[1 4
×1.2],3 4
=40.5×4×0.9,
=145.8.