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(1)1.25×17.6+36÷0.8+2.64×12.5(2)9998+998+99+9+6(3)267+123×894894×124−627(4)75×4.67+17.9×2.5(5)1991×199219921992-1992×199119911991(6)12+16+112+120+130.

题目详情
(1)1.25×17.6+36÷0.8+2.64×12.5          
(2)9998+998+99+9+6
(3)
267+123×894
894×124−627
                    
(4)75×4.67+17.9×2.5
(5)1991×199219921992-1992×199119911991          
(6)
1
2
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1
6
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1
12
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1
20
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1
30
▼优质解答
答案和解析
(1)1.25×17.6+36÷0.8+2.64×12.5,
=1.25×17.6+36×1.25+26.4×1.25,
=1.25×(17.6+36+26.4),
=1.25×80,
=100;

(2)9998+998+99+9+6,
=(10000-2)+(1000-2)+(100-1)+(10-1)+6,
=(10000+1000+100+10)-(2+2+1+1-6),
=11110-0,
=11110;

(3)
267+123×894
894×124−627

=
267+123×894
894×(123+1)−627

=
267+123×894
894×123+894×1−627

=
267+123×894
894×123+267

=1;

(4)75×4.67+17.9×2.5
=(75÷3)×(4.67×3)+(17.9÷10)×(2.5×10),
=25×14.01+1.79×25,
=25×(14.01+1.79),
=25×15.8,
=395;

(5)1991×199219921992-1992×199119911991,
=1991×199219921992-1992×199119911991,
=1991×1992×100010001-1992×1991×100010001,
=1991×1992×(100010001-100010001),
=1991×1992×0,
=0;

(6)
1
2
+
1
6
+
1
12
+
1
20
+
1
30

=(1-
1
2
)+(
1
2
-
1
3
)+(
1
3
-
1
4
)+(
1
4
-
1
5
)+(
1
5
-
1
6
),
=1-
1
2
+
1
2
-
1
3
+
1
3
-
1
4
+
1
4
-
1
5
+
1
5
-
1
6

=1-
1
6

=
5
6