See ill tell you! It's really easy! Every number is bro g multiplied by 3 like 3 by 3 is 9 , 9 by 3 is 27 and 27 by 3 is 81 and so on so to get te ninth term just keep on multiplying the numbers by 3 , multiply 243 by 3 and what you get by3 and there you go with your ninth number!