Question

find the sum of n terms of the series:-5 + 11 + 19 + 29 + 41 + ............upto n terms

Answer 1

Let us writeSn=5+11+19+29+41.......+A(n-1)+A(n);Sn= 5+11+19+29+.....+A(n-2)+A(n-1)+A(n);on subtraction...