Prove by principal of mathematical induction
7+77+777...........to n terms=7/81(10 n+1 -9n-10) for all n∈N
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7 + 77 + 777 + … to n terms
Let Sn = 7 + 77 + 777 + … to n terms
Prove by principal of mathematical induction
7+77+777...........to n terms=7/81(10 n+1 -9n-10) for all n∈N