SOLUTION: the 6th term is 50 and the 11th term is 85 find the 21st term

Question 1074275: the 6th term is 50 and the 11th term is 85 find the 21st term
Answer by ikleyn(52788) (Show Source): You can put this solution on YOUR website!
.
The 6th term is 50 and the 11th term is 85. Find the 21st term .
~~~~~~~~~~~~~~~~~~~~~~~~~~

  =   = 50,   (1)
 =  = 85.   (2)

=====>  5d = 85 - 50 = 35.   ====>  d = 7.


 =  = 85 + 10*7 = 155.

Solved.

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".

RELATED QUESTIONS
The 5th term of an A.P is 9 and the 8th term is 27, find; the 6th term and the sum of the (answered by Edwin McCravy)

the 21st... (answered by richwmiller)