Pause the video again and see if you can figure it out. All right, well, let's figure out the derivative here. f prime of x is going to be equal to, derivative of e to the x with respect to x is e to the x, which I always find amazing, and so, and then plus one, and the derivative of this with respect to x is just zero. And then let's substitute this into our original differential equation. So f prime of x is e to the x plus one. Is that equal to f of x, which is e to the x plus x plus one minus x, minus x? And if that x cancels out with that x, it is indeed.