计算:(1)362+548×361362×548-186(2)1+11+2+11+2+3+11+2+3+4…+11+2+3+…+100.-数学

题目简介

计算:(1)362+548×361362×548-186(2)1+11+2+11+2+3+11+2+3+4…+11+2+3+…+100.-数学

题目详情

计算:
(1)
362+548×361
362×548-186

(2)1+
1
1+2
+
1
1+2+3
+
1
1+2+3+4
…+
1
1+2+3+…+100
题型:解答题难度:中档来源:不详

答案

(1)class="stub"362+548×361
362×548-186

=class="stub"362+548×361
361×548+548-186

=class="stub"362+548×361
361×548+362

=1;

(2)1+class="stub"1
1+2
+class="stub"1
1+2+3
+class="stub"1
1+2+3+4
…+class="stub"1
1+2+3+…+100

=class="stub"2
1×2
+class="stub"2
2×3
+class="stub"2
3×4
+class="stub"2
4×5
+…+class="stub"2
100×101

=2×(1-class="stub"1
2
+class="stub"1
2
-class="stub"1
3
+class="stub"1
3
-class="stub"1
4
+class="stub"1
4
-class="stub"1
5
+…+class="stub"1
100
-class="stub"1
101
),
=2×(1-class="stub"1
101

=2×class="stub"100
101

=class="stub"200
101

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