The fifth term of an arithmetic sequence is 20 and the twelfth term is 41.
(a) (i) find the common difference.
(ii) find the first term of the sequence.
(b) calculate the eighty-fourth term.
(c) calculate the sum of the first 200 terms.

Click an item in the list or group of pictures at the bottom of the problem and, holding the button down, drag it into the correct position in the answer box. release your mouse button when the item is place. if you change your mind, drag the item to the trashcan. click the trashcan to clear all your answers. solve this quadratic equation using the quadratic formula. 2x2 - 2x=1 need asap