SOLUTION: find the sum of all integers between 50and500 which are divisible by 7.

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Question 1072281: find the sum of all integers between 50and500 which are divisible by 7.
Answer by ikleyn(52898) About Me  (Show Source):
You can put this solution on YOUR website!
.
Arithmetic progression.

The first term is 56.

The common difference is 7.

The last term is 497.

The number of the terms is n = %28497+-+56%29%2F7 + 1.

The rest is on you.

For the introductory lessons on arithmetic progressions see
    - Arithmetic progressions
    - The proofs of the formulas for arithmetic progressions
in this site.

There is a bunch of lessons on arithmetic progressions in this site:
    - Arithmetic progressions
    - The proofs of the formulas for arithmetic progressions
    - Problems on arithmetic progressions
    - Word problems on 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".