SOLUTION: Find the first term & commmon difference if : 4th term is 11; 10th term is 29

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Question 1087945: Find the first term & commmon difference if : 4th term is 11; 10th term is 29
Answer by ikleyn(52803) About Me  (Show Source):
You can put this solution on YOUR website!
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Between 4th and 10th terms, there is a room  for 6  (= 10-4)  "d"  (=common differences). 

So  6d = 29 - 11 = 18,  which implies d = 18%2F6 = 3.


Thus you found the common difference d:  it is d = 3.


Then a%5B1%5D = a%5B4%5D - 3d = 11 - 3*3 = 2.


Answer. The first term is 2. The common difference is 3.


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".