Question

arithmetic sequences..



Identify the 42nd term of an arithmetic sequence where a1 = -12 and a27 = 66.
70
72
111
114
help?

Answer 1

first we will need to find difference to do so,

66-(-12)
-------------
27-1

Answer 2

once you find difference( we will call it d) from above

a_42=a_1+ d *41

Answer 3

okay..im following

Answer 4

so what did you find for d

Answer 5

not sure. I thought you were going through it cause I don't really understand these and I was looking for an explanation...

Answer 6

to find the difference , evaluate this

66-(-12)
-------------
27-1

Answer 7

3?

Answer 8

yes

Answer 9

so you know the first term value a_1=-12, you know the difference between each sucessive term, so

a_42= a_1+ 3* 42

a_42=-12+3*42

Answer 10

114??

Answer 11

yes

Answer 12

thank you!

Answer 13

np