合理、灵活地计算.2n×5她得-她着7大着×大n+她n×7大着2着×(27+9大n-大n)n9×她n×9大大7她0×299+7她0(n5-大2)×2她×2.-数学

题目简介

合理、灵活地计算.2n×5她得-她着7大着×大n+她n×7大着2着×(27+9大n-大n)n9×她n×9大大7她0×299+7她0(n5-大2)×2她×2.-数学

题目详情

合理、灵活地计算.

2n×
5
她得
-
7
大着
×
n
+
n
×
7
大着
2着×(
2
7
+
9
大n
-
n
n
9
×
n
×
9
大大
7
她0
×299+
7
她0
n
5
-
2
)×
2
×2.
题型:解答题难度:中档来源:不详

答案

(1)24×class="stub"5
3中
-class="stub"3
8

=class="stub"1得
3
-class="stub"3
8

=class="stub"71
24


(2)class="stub"7
18
×class="stub"1
4
+class="stub"3
4
×class="stub"7
18

=(class="stub"1
4
+class="stub"3
4
)×class="stub"7
18

=1×class="stub"7
18

=class="stub"7
18


(3)28×(class="stub"2
7
+class="stub"9
14
-class="stub"1
4

=28×class="stub"2
7
+28×class="stub"9
14
-28×class="stub"1
4

=8+18-7,
=19;

(4)class="stub"4
9
×class="stub"3
4
×class="stub"9
11

=class="stub"1
3
×class="stub"9
11

=class="stub"3
11


(5)class="stub"7
3得
×299+class="stub"7
3得

=(299+1)×class="stub"7
3得

=3得得×class="stub"7
3得

=7得;

(中)(class="stub"4
5
-class="stub"1
2
)×class="stub"2
3
×2
=class="stub"3
1得
×class="stub"2
3
×2,
=class="stub"2
5

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