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April 13th, 2019, 02:29 AM   #1
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the sum

Find the sum of
1+11+111+1111+ .....1.....1
to the n th term in term of n.
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April 13th, 2019, 05:53 AM   #2
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Enter "1+11 + 111+1111" here:
The On-Line Encyclopedia of Integer Sequences® (OEIS®)
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April 13th, 2019, 05:56 AM   #3
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$(10^{n+1} - 9n - 10)/81$
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April 13th, 2019, 07:02 AM   #4
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1+11+111+1111+11111+.....
1/9(9+99+999+9999+99999+......)
=1/9(10-1+10^2-1+10^3-1+.......)
=1/9(10(10^n-1)/9-n)=(10^(n+1)-9n-10)/81
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