M and B Values from Linear Curve Fit

I was hoping someone could explain how to get the M and B values of a line from a curve fit. I haven't used the curve fit tool but have used polyfit and polyval and then plotted this.

I'm just not sure how to export the equation of the line, well at least the grade and constant values

[Kevin Chng]

Do you have any tried code for it?

[HoboHarry]

All good thankyou. worked it out