Which rule will find the nth term of an arithmetic sequence with a rate of increase equal to 1/2 and a6 = 18?

A. an = 30 + B. an = C. an = 15 − D. an = 15 +

Question

Which rule will find the nth term of an arithmetic sequence with a rate of increase equal to 1/2  and a6 = 18?

A. an = 30 +   B. an =   C. an = 15 −   D. an = 15 +

mathmate · Answer

I believe all the responses should read:
A. an=30+n/2
B. an=n/2
C. an=15-n/2
D. an=15+n/2

anonymous · Answer

yes thank you , you would be correct haha i messed up. but do you have the awnser please?

amistre64 · Answer

why dont you just use n=6 to see if you get 18 as a result now?

anonymous · Answer

im sorry , i dont understand..

amistre64 · Answer

thats rather sad :/

replace the "n" with the value of "6" and work the math .... if you end up with a6 = 18 then youve got the correct option.

anonymous · Answer

I think i got it ! thanks ! i first did it and thought it was A  then i think i realised i did the problem in the wrong order cause you solve the division first so then i got D .  I think the awnser is D

mathmate · Answer

Yes, you have the correct answer.  Hope you worked out the way @amistre64 suggested.

amistre64 · Answer

15 + 6/2 = 18,  i like D as well :)

anonymous · Answer

Thank you! (: