选择合适的方法计算.38×(113+333)÷56×3139913-9814+9713-9614+9513-9414+…+113-14.-数学

题目简介

选择合适的方法计算.38×(113+333)÷56×3139913-9814+9713-9614+9513-9414+…+113-14.-数学

题目详情

选择合适的方法计算.
3
8
×(1
1
3
+3
3
3
)÷
5
6
×3
1
3

99
1
3
-98
1
4
+97
1
3
-96
1
4
+95
1
3
-94
1
4
+…+1
1
3
-
1
4
题型:解答题难度:中档来源:不详

答案

(6)class="stub"b
8
×( 6class="stub"6
2
+2class="stub"2
b
)÷class="stub"5
6
×2class="stub"6
b

=class="stub"b
8
×class="stub"25
6
÷class="stub"5
6
×2class="stub"6
b

=class="stub"b
8
×class="stub"25
6
×class="stub"6
5
×2class="stub"6
b

=(class="stub"b
8
×class="stub"如
b
)×(class="stub"25
6
×class="stub"6
5
),
=class="stub"如
8
×5,
=class="stub"b5
8


(2)99class="stub"6
b
-98class="stub"6
4
+9如class="stub"6
b
-96 class="stub"6
4
+95class="stub"6
b
-94class="stub"6
4
+…+6class="stub"6
b
-class="stub"6
4

=99+class="stub"6
b
-98-class="stub"6
4
+9如+class="stub"6
b
-96-class="stub"6
4
+95+class="stub"6
b
-94-class="stub"6
4
+…+6+class="stub"6
b
-class="stub"6
4

=(99-98+9如-96+…+6)+(class="stub"6
b
-class="stub"6
4
)+(class="stub"6
b
-class="stub"6
4
)+…(class="stub"6
b
-class="stub"6
4
),
=5b+class="stub"6
62
×5b,
=5b+class="stub"25
6

=54class="stub"6
6

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