The slope of a line between two points [tex](x_1, y_1)[/tex] and [tex](x_2, y_2)[/tex] is given by [tex]\frac{y_2 - y_1}{x_2 - x_1}[/tex]. You can think of this as either rise/run or change in y divided by change in x.
Here, the slope is [tex]\frac{6-4}{2-1}[/tex], which is equal to 2.
