You posted a similar question a while ago: http://www.mathhelpforum.com/math-he...d-value-k.html. The method shown to you there is the same as the method required here .... The current question requires you to do the same thing -twice- to gettwoequations:

Substitute each point into the equation. Gettwoequations in the unknowns m and b. Solve the two equations simultaneously for m and b.