The fourth term in an arithmetic sequence is 18 and the seventh term is 39. If the first term is a, which is an equation for the nth term of this sequence?

40 i don’t know lololol

      2

  2 is to go somewhat to the top right of a because it is squared    

v= a h/3

-3(b-8)-5=9(b+2)+1

distribute

-3b+24-5=9b+18+1

add/ subtract

-3b+20=9b+19

20-19= 1

-3b+1=9b

9b+3b= 12b

1=12b

1 divided by 12 = 1/12

answer: 1/12 = b