So let's see, if we were to unfactor the derivative, I'm just gonna solve for dy dx. So I'm gonna factor it out. I'm gonna get dy dx times x plus y, x plus y is equal to x. Now if I were to divide both sides by x plus y, I'm gonna get dy dx is equal to x over x plus y. And here, my algebraic toolkit of how do I separate x and y so I can write this as a function of x times a function of y, not obvious to me here. So this one is not separable. There's only the first one and the third one.