# data[].attributes.body
part 2

# data[].attributes.body
= 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

# data[].attributes.body
7(1+11+111+...)
=7/9(9+99+...)
=7/9[(10-1)+(10²-1)+..)]
=7/9[(10+10²+..)+(-1(n))]
S n=a(r n-1)/r-1
=10(10n-1)/10-1
=10/9(10n-1)
7/9[10/9(10n-1) -n]
=7/81(10 n+1-9n-10)
Therefore, the sum of the sequence 7,77,..to n terms is 7/81(10 n+1-9n-10)

# data[].attributes.body
Abhipsa 11G1

# data[].attributes.body
=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)

# data[].attributes.body
sum=7/9[10(10^n-1)/9-n]

# data[].attributes.body
ANSWER
7/9(10(10^n-1)-n/9 //

# data[].attributes.body
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)

# data[].attributes.body
part 1