.
Between 4th and 10th terms, there is a room for 6 (= 10-4) "d" (=common differences).
So 6d = 29 - 11 = 18, which implies d = = 3.
Thus you found the common difference d: it is d = 3.
Then = - = 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".