SOLUTION: how do I find the sum of the sequence in this problem; 40+41+42+43+...137

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Question 1054237: how do I find the sum of the sequence in this problem;
40+41+42+43+...137
Found 2 solutions by Fombitz, ikleyn:
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
You can find the sum from 1-137 and then subtract the sum from 1-39. Then you will have the sum from 40-137.
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1+2+3+...+39+40+41+...+136+137
1+2+3+...+39
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.......................40+41+...+136+137

Answer by ikleyn(52792) About Me  (Show Source):
You can put this solution on YOUR website!
.
how do I find the sum of the sequence in this problem;
40+41+42+43+...137
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Arithmetic progression.

The first term 40.

The common difference 1.

The number of terms = 137 - 39 = 98.

Apply the formula for the sum of an arithmetic progression.

S = %28%28a%5B1%5D%2Ba%5B38%5D%29%2F2%29%2An = %2840%2B137%29%2F2%2A98 = use your calculator.

On arithmetic progressions see the lessons
    - Arithmetic progressions
    - The proofs of the formulas for arithmetic progressions
    - Problems on arithmetic progressions
    - Word problems on arithmetic progressions
    - Chocolate bars and arithmetic progressions
    - Mathematical induction and arithmetic progressions
    - One characteristic property of arithmetic progressions
    - Solved problems on arithmetic progressions


Also, you have this free of charge online textbook in ALGEBRA-II in this site
    - ALGEBRA-II - YOUR ONLINE TEXTBOOK.

The referred lessons are the part of this online textbook under the topic "Arithmetic progressions".