Question

How do you use sigma notation to write the sum for 13(1)+13(2)+13(3)+...+13(9)?

Answer 1

13(6)is correct answer

Answer 2

$13(1 + 2 + 3 + .... + 9) \\ a \frac{}{r} = 13.r \\ \\ 13 \sum _{r = 1} r$