1/3x - 125 = 2
1/3x = 2 + 125
1/3x = 127
x = 127 times 3 (if you multiply both sides by three the 1/3 in front of the x will cancel off and whatever you do to one side of the equation you have to do to both so that is why you multiply the 127 times 3)
x = 381
hope this helps :)