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# use sigma notation to write the sum 9/(i+1)+9/(i+2)+9/(i+3)+....+9/(i+14)

use sigma notation to write the sum 9/(i+1)+9/(i+2)+9/(i+3)+....+9/(i+14)

### 2 Answers by Expert Tutors

Francisco E. | Francisco; Civil Engineering, Math., Science, Spanish, Computers.Francisco; Civil Engineering, Math., Sci...
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use sigma notation to write the sum 9/(i+1)+9/(i+2)+9/(i+3)+....+9/(i+14)
The so called sigma notation is a synoptic way of expressing a series of expressions that are being added and have some characters that follow a cadence or are a series of numbers easily expressed
In our case the expression will be:
j=1j=14 (9/(i+j)) and this will develop the series  expressed above.
Ira S. | Bilingual math tutor and much moreBilingual math tutor and much more
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I have no sigma on my keyboard so I will use & instead. What sigma notation does is replaces values from its lower limit to its upper limit into an expression that DOES NOT change. So, the numbers that are changing in your expression start at 1 and increase to 14. These are the upper and lower limits for the sigma. This is also where you're going to replace those numbers with a variable, usually i, but since you already have an i in your expression, I'll use j. So your answer is
14
&      9/(i+j) ....
j=1
Checking, replace j with 1, then 2, then3...up to 14 and you'll get 9/(i+1) then 9/(i+2) up to 9/(i+14) which needs to get added which is your original expression.