Well, I can cut at most, we can see here the length right over here, this pink color, this mauve color, is 20 minus two x. So this has got to be greater than zero. This is always going to be shorter than the 30 minus two x. But the 20 minus two x has to be greater than or equal to zero. You can't cut more cardboard than there is. Or you could say that 20 has to be greater than or equal to two x. Or you could say that 10 is going to be greater than or equal to x, which is another way of saying that x is going to be less than or equal to 10.