The plot function creates a 2D plot with the slope-intercept form of the equation, and the (x,-10,10) part specifies the range of the graph, between the x values of -10 and 10.

How to Calculate Y-Intercept in Excel. The y-intercept is the point at which a linear equation crosses the y-axis on the x=0 plot point. The equation to determine both the slope and the y ...

That is the the basic form of linear regression by hand. Note that there ARE other ways to do this - more complicated ways (assuming different types of distributions for the data).