-52 is the answer because you have to isolate 1/3x by adding 2/3 to -18 then you have to multiply -18/1 by 3 so you can have a common denominator. After, you should have -54/3 plus 2/3 you subtract the two and get -52/3. You then have 1/3x equals -52/3. You divide 1/3x by -52/3 which means you have to multiply by the reciprocal of 1/3x which is 3/1x. You multiply that by -52/3. The threes cancel out and you're left with x = -52.
