Answer:
S
ThenSn=n(a1+an)2Sn=n(a1 + an)2 , where nn is the number of terms, a1a1 is the first term and anan is the last term. The sum of the first nn terms of an arithmetic sequence is called an arithmetic series .
Step-by-step explanation:
Answer:
for number one, look at the screenshot attached, that should help
Step-by-step explanation:
199, it rounds to 200 because it's closer to 200 than 100. It is also closer to 200 than to 190. And finally, 1 + 9 + 9 = 19
Answer:
I cant see it....
Step-by-step explanation:
I cant see it....
