Find the first 20 terms in the arithmetic series -6-12-

Keep subtracting 6 until you hit the 20th term. Hope this helps

6, 12, 18, 24, 30, 36, 42, 48, 54, 60, 66, 72, 78, 84, 90, 96, 102, 108, 114, 120, 126, 132, 138, 144, 150

I did a little extra for you, b ut all you have to do is add 6 each tim :)

Hope this helped!