SOLUTION: Please help me this problem is driving me crazy. Write the sum using sigma notation: 1/1&#8901;2+1/2&#8901;3+1/3&#8901;4+&#8943;+1/219&#8901;220= A &#8721; B n=1 , where

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Question 1025112: Please help me this problem is driving me crazy.
Write the sum using sigma notation:
1/1⋅2+1/2⋅3+1/3⋅4+⋯+1/219⋅220=
A
∑ B
n=1
, where
A=

B=

Found 2 solutions by richard1234, ikleyn:
Answer by richard1234(7193) (Show Source):
You can put this solution on YOUR website!
Note that each term is of the form 1/(n*(n+1)) where n ranges from 1 to 219 (*not* 220).

In fact, the sum is equal to 1 - (1/220) = 219/220. But that is a completely different problem.

Answer by ikleyn(52788) (Show Source):
You can put this solution on YOUR website!
.
Please help me this problem is driving me crazy.
Write the sum using sigma notation:
1/1⋅2+1/2⋅3+1/3⋅4+⋯+1/219⋅220=
A
∑ B
n=1
, where
A=

B=
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

A = 219. B = ,

SOLUTION: Please help me this problem is driving me crazy. Write the sum using sigma notation: 1/1&#8901;2+1/2&#8901;3+1/3&#8901;4+&#8943;+1/219&#8901;220= A &#8721; B n=1 , where

SOLUTION: Please help me this problem is driving me crazy. Write the sum using sigma notation: 1/1⋅2+1/2⋅3+1/3⋅4+⋯+1/219⋅220= A ∑ B n=1 , where