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脱式计算,能简算的必须简算.0.25×1.25×326.75×2.9+42.5×0.29-2.978÷[(35+110)×54]35.6-1.8-15.6-7.21999+999×9990.5×[515÷(3-2.5×78)].
题目详情
脱式计算,能简算的必须简算.
0.25×1.25×32
6.75×2.9+42.5×0.29-2.9
÷[(
+
)×
]
35.6-1.8-15.6-7.2
1999+999×999
0.5×[5
÷(3-2.5×
)].
0.25×1.25×32
6.75×2.9+42.5×0.29-2.9
7 |
8 |
3 |
5 |
1 |
10 |
5 |
4 |
35.6-1.8-15.6-7.2
1999+999×999
0.5×[5
1 |
5 |
7 |
8 |
▼优质解答
答案和解析
(1)0.25×1.25×32
=0.25×1.25×(4×8)
=(0.25×4)×(1.25×8)
=1×10
=10;
(2)6.75×2.9+42.5×0.29-2.9
=6.75×2.9+4.25×2.9-2.9
=(6.75+4.25-1)×2.9
=10×2.9
=29;
(3)
÷[(
+
)×
]
=
÷[
×
]
=
÷
=1;
(4)35.6-1.8-15.6-7.2
=(35.6-15.6)-(1.8+7.2)
=20-9
=11;
(5)1999+999×999
=(1000+999)+999×999
=1000+999×(1+999)
=1000+999×1000
=1000×(1+999)
=1000×1000
=1000000;
(6)0.5×[5
÷(3-2.5×
)]
=0.5×[5
÷(3-
)]
=0.5×[5
÷
]
=0.5×
=3.2.
=0.25×1.25×(4×8)
=(0.25×4)×(1.25×8)
=1×10
=10;
(2)6.75×2.9+42.5×0.29-2.9
=6.75×2.9+4.25×2.9-2.9
=(6.75+4.25-1)×2.9
=10×2.9
=29;
(3)
7 |
8 |
3 |
5 |
1 |
10 |
5 |
4 |
=
7 |
8 |
7 |
10 |
5 |
4 |
=
7 |
8 |
7 |
8 |
=1;
(4)35.6-1.8-15.6-7.2
=(35.6-15.6)-(1.8+7.2)
=20-9
=11;
(5)1999+999×999
=(1000+999)+999×999
=1000+999×(1+999)
=1000+999×1000
=1000×(1+999)
=1000×1000
=1000000;
(6)0.5×[5
1 |
5 |
7 |
8 |
=0.5×[5
1 |
5 |
35 |
16 |
=0.5×[5
1 |
5 |
13 |
16 |
=0.5×
32 |
5 |
=3.2.
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