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
[tex]\displaystyle \sum_{n=1}^{10} {2n} = 2*1 + 2*2 +2*3+2*4+...+2*10=2+4+6+8+...+20[/tex]
thanks
