Question

Find the 20th term of the following sequence.

-6, -4, -2, 0, ...
1)32
2)44
3)46

Answer 1

one way you can do this is count down from -6 by 2's til you get to the 20th number.

Answer 2

\[
a_1=-6\\
a_2=a_1+2=-4\\
a_3=a_2+2=a_1+2(2)=-2\\

\]

Answer 3

well whats the easiest way to do it?

Answer 4

What is \[a_n\]?

Answer 5

idk

Answer 6

well then

Answer 7

\[
a_n=a_1+(n-1)2=-6+2(n-1)
\]

Answer 8

What is \[a_{20}\]?

Answer 9

i think i might be right but isnt it like 20a or something like that but its been a while since ive done algebra so i really dont know

Answer 10

\[a_{20} =-6 + 2(20-1)=-6+38=32

\]

Answer 11

ok