The answer is 23 1/3. First, you need to add 280 to both sides of the equations in order cancel out 280 and get 12x by itself. But remember whatever you do to one side of an equation, you must to do the other. So now you have 12x=280. Now divide both sides of the equation by 12 in order to get x completely isolated. 280 divided by twelve is 23 1/3.
