Show that the sequence is arithmetic. Find the common difference, and write out the rst four terms. {on} = {4 9n} Show that the sequence is arithmetic. d = C"n. _ ICn 1 = (4 - 9n} -( ) (Simplify your answers.) Find the rst term and the common difference of the arithmetic sequence described. Give a recursive formula for the sequence. Find a formula for the nth term. 5th term is 2; 21st term is 66 What is the rst term of the sequence? Find the rst term and the common difference of the arithmetic sequence described. Give a recursive formula for the sequence. Find a formula for the nth term. 6th term is 13; 17th term is 75 What is the rst term of the sequence? Find the rst term and the common difference of the arithmetic sequence described. Give a recursive formula for the sequence. Find a formula for the nth term. 15th term is 0; 55th term is 120 The rst term is a1 = The common difference is d =