Question

What is the 20th term of the arithmetic sequence 3, –3, –9, … ?

Answer 1

whats the pattern

Answer 2

whats the 4th number tell me

Answer 3

-15?

Answer 4

ok good so its losing 6 everytime

Answer 5

can you write an equation that is losing 6 every number and starts from 3

Answer 6

20 = 9 - 6*20

Answer 7

hmm

Answer 8

so it would be -111?

Answer 9

yep works

Answer 10

k thanks

Answer 11

good job

Answer 12

just a suggest for future

Answer 13

write it like Sn = 9-6n
Sn meaning number is sequence

Answer 14

when you write it in terms of n you can do quick checks to see if the equation works

Answer 15

ya, i put 20 for the sn

Answer 16

S1 = 9-6(1) = 3 works for 1st term and so on

Answer 17

im just try to get you to start with these habits, it wont seem like much to you, but ull see its gonna clear up your work a lot, and ull start to think more like a mathematician

Answer 18

thanks so much

Answer 19

anytime :)