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(2011•郑州模拟)能简算的要简算:(1)432×99-568(2)1429÷4-(3+5÷9)(3)51×68×78÷(17×34×13)(4)1417×(223-0.75)+1512÷1721.

题目详情
(2011•郑州模拟)能简算的要简算:
(1)432×99-568
(2)14
2
9
÷4-(3+5÷9)
(3)51×68×78÷(17×34×13)
(4)1
4
17
×(2
2
3
-0.75)+15
1
2
÷
17
21
▼优质解答
答案和解析
(1)432×99-568
=432×(100-1)-568,
=432×100-432-568,
=43200-(432+568),
=43200-1000,
=42200;

(2)14
2
9
÷4-(3+5÷9)
=
128
9
×
1
4
-(3+
5
9
),
=
32
9
-
32
9

=0;

(3)51×68×78÷(17×34×13)
=51×68×78÷17÷34÷13,
=(51÷17)×(68÷34)×(78÷13),
=3×2×6,
=36;

(4)1
4
17
×(2
2
3
-0.75)+15
1
2
÷
17
21

=
21
17
×(
8
3
-
3
4
)+
31
2
×
21
17

=
21
17
×
23
12
+
31
2
×
21
17

=(
23
12
+
31
2
)×
21
17

=(
23
12
+
186
12
)×
21
17

=
209
12
×
21
17

=
1463
68