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计算:12+221×2+22+322×3+32+423×4+42+524×5+…+20122+201322012×2013=.

题目详情
计算:
12+22
1×2
+
22+32
2×3
+
32+42
3×4
+
42+52
4×5
+…+
20122+20132
2012×2013
=______.
12+22
1×2
+
22+32
2×3
+
32+42
3×4
+
42+52
4×5
+…+
20122+20132
2012×2013
=______.
12+22
1×2
12+2212+2212+2212+222+22222221×21×2
22+32
2×3
22+3222+3222+3222+322+32323222×32×3
32+42
3×4
32+4232+4232+4232+422+42424223×43×4
42+52
4×5
42+5242+5242+5242+522+52525224×54×5
20122+20132
2012×2013
20122+2013220122+2013220122+2013220122+201322+20132201322013222012×20132012×2013
▼优质解答
答案和解析
12+22
1×2
+
22+32
2×3
+
32+42
3×4
+
42+52
4×5
+…+
20122+20132
2012×2013

=(2+
1
1×2
)+(2+
1
2×3
)+…+(2+
1
2012×2013
),
=2×2012+(1-
1
2013
),
=4024+
2012
2013

=4024
2012
2013
12+22
1×2
12+2212+2212+222+2221×21×21×2+
22+32
2×3
22+3222+3222+322+3222×32×32×3+
32+42
3×4
32+4232+4232+422+4223×43×43×4+
42+52
4×5
42+5242+5242+522+5224×54×54×5+…+
20122+20132
2012×2013
20122+2013220122+2013220122+201322+2013222012×20132012×20132012×2013,
=(2+
1
1×2
)+(2+
1
2×3
)+…+(2+
1
2012×2013
),
=2×2012+(1-
1
2013
),
=4024+
2012
2013

=4024
2012
2013
1
1×2
1111×21×21×2)+(2+
1
2×3
)+…+(2+
1
2012×2013
),
=2×2012+(1-
1
2013
),
=4024+
2012
2013

=4024
2012
2013
1
2×3
1112×32×32×3)+…+(2+
1
2012×2013
),
=2×2012+(1-
1
2013
),
=4024+
2012
2013

=4024
2012
2013
1
2012×2013
1112012×20132012×20132012×2013),
=2×2012+(1-
1
2013
),
=4024+
2012
2013

=4024
2012
2013
1
2013
111201320132013),
=4024+
2012
2013

=4024
2012
2013
2012
2013
201220122012201320132013,
=4024
2012
2013
2012
2013
201220122012201320132013.