SOLUTION: the first term of an arithmetic sequence is -5, and the twelfth term is 17 find the common difference

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Question 1079451: the first term of an arithmetic sequence is -5, and the twelfth term is 17 find the common difference
Answer by ikleyn(52787) About Me  (Show Source):
You can put this solution on YOUR website!
.
a%5B1%5D = -5,

a%5B12%5D = a%5B1%5D + 11*d = -5 + 11*d.


So, you have an equation

-5 + 11d = 17.

Solve it for d, the common difference.


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
    - 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".