You're just going to see it in a different way. So this whole video I'm just going to rewrite this definition of covariance right over here. So this is going to be the same thing as the expected value of, and I'm just going to multiply these two binomials in here. So the expected value of our random variable X times our random variable Y minus, well I'll just do the X first. So plus X times the negative expected value of Y. So I'll just say minus X times the expected value of Y. And that negative sign comes from this negative sign right over here.