Four x to the third power, four x to the third minus five x to the fourth, minus five x to the fourth is equal to zero. Let's see, we can factor out an x to the third. We have x to the third times four minus five x is equal to zero. So this is going to happen when x is equal to zero. That I could, let me not skip steps. So this is going to happen when x to the third is equal to zero, or four minus five x is equal to zero. For x to the third equaling zero, well that's only gonna happen when x is equal to zero.