absolute value just tells you how many units a value is from 0 on a number line. |-1|, for example, is 1 unit away from the number line. |383| is 383 units away. with that being said, the answer to absolute value equations is set up like so:
x + 6 = 18 or x + 6 = -18
so basically, the absolute value of (x + 6) is 18 units away from 0 on a number line, but it could be 18 units in the positive or negative direction, so you have to look for both by setting it to both -18 and 18. your answer is C.
