This right over here I can rewrite as 2x minus 2y. So let me do that. So I can save some space. This is 2x minus 2y if I just distribute the 2. And now I can distribute the 2x minus 2y onto each of these terms. So 2x minus 2y times 1 is just going to be 2x minus 2y. And then 2x minus 2y times negative dy dx, that's just going to be negative 2x minus 2y.