11G1 Starter Activity 29th SEP 2020 Math. by Lakshmi Sathyanarayanan https://padlet.com/boomasathyanarayanan/x8pntnc7ckwub1vb Find the sum of the sequence 7, 77, 777, 7777, ... to n terms. en-us 2020-09-29 04:23:32 UTC 2024-06-09 09:16:58 UTC hello@padlet.com Ann https://padlet.com/boomasathyanarayanan/x8pntnc7ckwub1vb/wish/787109709 part 1]]> 2020-09-29 08:37:32 UTC https://padlet.com/boomasathyanarayanan/x8pntnc7ckwub1vb/wish/787109709 Soha 11G1 https://padlet.com/boomasathyanarayanan/x8pntnc7ckwub1vb/wish/787109990 7+77+777+7777....n terms 
solution:
=7(1+11+111+1111...n terms)
multiply and divide by 9 
=7/9 [(10-1) + (10²-1) + (10³-1) ... n terms]
=7/9 [ (10 + 10² + 10³...) - (1+1+1...n terms)]
=7/9 (10(10ⁿ-1/9) - n)
=7/81 (10^n+1 - 10 - 9n)
hence sum of n terms = 
7/81 (10^n+1 - 10 - 9n)]]> 2020-09-29 08:37:43 UTC https://padlet.com/boomasathyanarayanan/x8pntnc7ckwub1vb/wish/787109990 Naillya-11G1 gvnaillya5 https://padlet.com/boomasathyanarayanan/x8pntnc7ckwub1vb/wish/787110625 ANSWER
7/9(10(10^n-1)-n/9 //]]> 2020-09-29 08:38:05 UTC https://padlet.com/boomasathyanarayanan/x8pntnc7ckwub1vb/wish/787110625 Nameera https://padlet.com/boomasathyanarayanan/x8pntnc7ckwub1vb/wish/787111622 7(1+11+111+...)
=7/9(9+99+...)
=7/9[(10-1)+(102-1)+..)]
=7/9[(10+102+..)+(-1(n))]
Sn=a(rn-1)/r-1
    =10(10n-1)/10-1
    =10/9(10n-1)
7/9[10/9(10n-1) -n]
=7/81(10n+1-9n-10)
Therefore, the sum of the sequence 7,77,..to n terms is 7/81(10n+1-9n-10)]]> 2020-09-29 08:38:41 UTC https://padlet.com/boomasathyanarayanan/x8pntnc7ckwub1vb/wish/787111622 naeema https://padlet.com/boomasathyanarayanan/x8pntnc7ckwub1vb/wish/787112631 sum=7/9[10(10^n-1)/9-n]]]> 2020-09-29 08:39:15 UTC https://padlet.com/boomasathyanarayanan/x8pntnc7ckwub1vb/wish/787112631 Ginan https://padlet.com/boomasathyanarayanan/x8pntnc7ckwub1vb/wish/787112938 =7/9 [(10-1) + (10²-1) + (10³-1) ... n terms]
=7/9 [ (10 + 10² + 10³...) - (1+1+1...n terms)]
=7/9 (10(10ⁿ-1/9) - n)
=7/81 (10^n+1 - 10 - 9n)

]]> 2020-09-29 08:39:28 UTC https://padlet.com/boomasathyanarayanan/x8pntnc7ckwub1vb/wish/787112938 Hanna 2.0 https://padlet.com/boomasathyanarayanan/x8pntnc7ckwub1vb/wish/787119748 2020-09-29 08:43:19 UTC https://padlet.com/boomasathyanarayanan/x8pntnc7ckwub1vb/wish/787119748 https://padlet.com/boomasathyanarayanan/x8pntnc7ckwub1vb/wish/787121003 Abhipsa 11G1]]> 2020-09-29 08:44:04 UTC https://padlet.com/boomasathyanarayanan/x8pntnc7ckwub1vb/wish/787121003 Levita 11G1 https://padlet.com/boomasathyanarayanan/x8pntnc7ckwub1vb/wish/787121671 2020-09-29 08:44:27 UTC https://padlet.com/boomasathyanarayanan/x8pntnc7ckwub1vb/wish/787121671 Hanna 1.0 https://padlet.com/boomasathyanarayanan/x8pntnc7ckwub1vb/wish/787122089 2020-09-29 08:44:42 UTC https://padlet.com/boomasathyanarayanan/x8pntnc7ckwub1vb/wish/787122089 Ria https://padlet.com/boomasathyanarayanan/x8pntnc7ckwub1vb/wish/787122842 2020-09-29 08:45:07 UTC https://padlet.com/boomasathyanarayanan/x8pntnc7ckwub1vb/wish/787122842 Priya https://padlet.com/boomasathyanarayanan/x8pntnc7ckwub1vb/wish/787124858 = 7 + 77 +777 ...n terms
= 7(1+11+111 ... n terms)
= 7/9(9+99+999 ... n terms)
= 7/9[(10-1)+(10^2-1)+(10^3-1)+...n terms)
=7/9[10 + 10]]> 2020-09-29 08:46:12 UTC https://padlet.com/boomasathyanarayanan/x8pntnc7ckwub1vb/wish/787124858 Ann https://padlet.com/boomasathyanarayanan/x8pntnc7ckwub1vb/wish/787126290 part 2]]> 2020-09-29 08:46:56 UTC https://padlet.com/boomasathyanarayanan/x8pntnc7ckwub1vb/wish/787126290