I would say that you cross multiply the fractions like you normally would, so you end up with 1.5x = 12x. Then if you were to solve for x, well you would divide x from both sides, and you end up with this:1.5 = 12Well, if I didn't know any better, 1.5 is not the same as 12! This means that it's a false statement, and the above equation is not true.Another way to look at it is to just plug a value in for x. Well, no matter what we put in, since both the denominators are exactly the same, and since the numerators don't change if we plug in a value for x, the fractions will never equal each other.Examples:1.5 = 12 1.5 = 12 1.5 = 12 5 5 2 2 8 8That's not true, neither is this one, and neither this one.You could plug values in forever, and you'd never get the two fractions to equal each other. Though if you needed to prove it, it'd suggest using the first method. ~ Azaler