Answer:
<h2><u>since </u><u>DE≅EF</u></h2>
<u>CD=</u><u>CF </u><u>(</u><u>cpct)</u>
<u>
</u>
<h2><u>hope</u><u> it</u><u> helps</u><u> you</u><u><</u><u>3</u></h2>
The wording of this question is a bit confusing... You can't write a sequence in sigma notation, but rather a series or sum. I think the question is asking you to write the sum of the sequence,

which would be

in sigma notation.
To do this, notice that the denominator in each term is a power of 2, starting with
and ending with
. So in sigma notation, this series is

233 base five = 2 x 5^2 + 3 x 5 + 3 x 1 = 2 x 25 + 15 + 3 = 50 + 18 = 68 base 10
11000 base two = 1 x 2^4 + 1 x 2^3 = 16 + 8 = 24 base ten
43E base twelve = 4 x 12^2 + 3 x 12 + 11 x 1 = 4 x 144 + 36 + 11 = 576 + 47 = 623 base ten
I worked it out and I got south Africa
I would like to ask you to go to the vet, or attempt to, as this might be a worm in the eye. The same thing happened to my dog.