And then what is our change in time? Over our change in time, well, that's going to be two minus one. Two minus one. Which is just going to be one hour. Over one hour. Or we could say that the slope of the line that connects these two points, let me do that in another color, the slope of, that's the same color, the slope of this line right over here, the slope right over here is 80 miles per hour. Slope is equal to 80 miles per hour.