Question

4. Choose the appropriate summation notation for the given arithmetic series. Then find the sum of the series.
3 + 6 + 9 + 12 + ...; 100th

Answer 1

a=3 ,d=3 ,L=100 ,where a=first term ,d=diffrence, L=last term.
then use the law :Sn=n/2(a+L) ,where n = number of all terms

Answer 2

Need more explanation ?