posted by Ellie on .
-Write the arithmetic sequence 21,13,5,-3... in the standard form:
why isnt this right?
You are close. You have an error:
a_n = 21 + (n - 1) - 8
a_n = 21 + (n - 1) * (-8)
oh yeah sorry i wrote that wrong i put -168-8n but it still said my answer was wrong
a_n = 21 + (n-1)*(-8)
Expand that using the distributive law.
The first term, 21, is not multiplied by -8. Only the terms in parenthesis are multiplied by -8.
i figured out what i was doing thank you so much!
You're very welcome.