Question

I am not sure how sigma notation works, can somebody explain how to solve this? It isn't the second choice.

Answer 1

Answer:

first answer is correct

Step-by-step explanation:

Hello, we want to write 2 + 4 + 6 + ... + 20

for n = 1, 2n = 2*1 =2

for n = 2, 2n = 2*2=4

for n = 3, 2n=2*3=6

etc

so

$\displaystyle \sum_{n=1}^{10} {2n} = 2*1 + 2*2 +2*3+2*4+...+2*10=2+4+6+8+...+20$

thanks