So assuming the underlined decimal is the second 8, let's answer the question.
Hundreds: 0 | Tens: 8 | ones: 3 | . | tenths: 5 | hundredths: 8 | thousandths: 5 | 10 thousandths: 1
So since the second 8 is in the hundredths place, we know it's either B or C.
When we round for 5, we always round up, so the answer would be 83.59
So the answer is B.
Hope this helped! If you have any more questions or don't understand please comment or DM me. :)
Answer: Choice A
S9 = (9/2)*(2+26)
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The formula is
Sn = (n/2)*(a1+an)
where
Sn = sum of the first n terms (nth partial sum)
n = number of terms
a1 = first term
an = nth term
In this case,
n = 9
a1 = 2 (plug in n = 1 into the formula an = 3n-1 and simplify)
an = a9 = 26 (plug n = 9 into the formula an = 3n-1 and simplify)
So,
Sn = (n/2)*(a1+an)
S9 = (9/2)*(2+26)
will help us find the sum of the first 9 terms of this arithmetic sequence
I think 2/4 but I'm not 100% sure sry
