one can model a linear line with the equation
y=Mx+b . given this equation, you can do 1 line of algebra to show M=y/x-b/x. But the way you stated your problem makes no sense. Please stop.
the equation M=y/x-b/x is just equal to F(x)=y=Mx + b where M is the slope and b is the y-intercept this is a point slope formula, the graph can be easily understood.............so simple !!!!!!!!!!!!!!!!