Answer: x = 4
Work: First, you must distribute the 1.50 to 8x and -12. The new equation you get after doing so is 12x - 18 = 30. Next, we are going to add 18 on both sides, cancelling on the side it was currently on. After cancelling, we get 12x = 48. Divide 12 on both side, and again cancelling on this side it's currently on, and you get x = 4.
Check: 1.50(8(4)-12) = 30. (After solving, you get 30) (check)
I hope this helps, and Happy Holidays! :)