Arithmetic Sequence

1. A sequence which consecutive terms have a common difference is a/ an _________________________

2. The number "d" in

 $a_n=a_1+\left(n-1\right)d$  is called the _____________________ of any two consecutive terms in an arithmetic sequence.

3. What is the common difference of the sequence 5, 9, 13, ... ?

4. Find the 15th term of the sequence

 $1,-4,-9,-14$  

5. The sum of the first n terms of an arithmetic sequence is called _______________.

6. Solve for the indicated term

 $a_{1\ }=\ ?\ \ ;\ \ d\ =\ 5\ \ ;\ \ a_{6\ }=\ 28$  

7. A stack of telephone poles has 30 poles in the bottom row. there are 29 poles in the second row, 28 in the next row, and so on. How many poles are there in the 26th row?

8. Find the arithmetic mean between 6 and 18.

9. Insert two arithmetic means between 21 and 33?

10. Find the indicated term of the arithmetic sequence

 $a_{1\ }=\ 5\ ;\ a_{4\ }=\ 11\ ;\ a_{6\ }=\ ?$