Algebra Answers - Arithmetic Sequences

 1. yes; -3
2. yes; -20
3. yes; -30
4. yes; -10
5. yes; -2
6. yes; 5

for #11-18, "an" means "a sub n" - there's no key for that...

11. 28, 38, 48, 58, 68;  an=28 + (n-1)10
12. -38, -138, -238, -338, -438;  an = -38 + (n-1)(-100)
13. -34, -44, -54, -64, -74;  an= -34 + (n-1)(-10)
14. 35, 39, 43, 47, 51;  an = 35 + (n-1)4

15.  -12.5, -13.6, -14.7, -15.8, -16.9;  an = -12.5 + (n-1)(-1.1)
16. -21, -51, -81, -101, -131;  an = -21 + (n-1)(-30)
17. -39, -31, -23, -15, -7;  an = -39 + (n-1)8
18.  -31, -38, -45, -52, -59; an = -31 + (n-1)(-7)