Question 790967
{{{p-y=m(h-x)}}} for some point (x,y), and m is slope.  The variable point is (h,p) and the axes are the h and the p axes.  Which (x,y) point you pick is your choice; either will work.  Filling the parts of the equation and choosing point (4,20), you get this, which will need some simplification:


{{{highlight(p-20=((76-20)/(17-4))(h-4))}}}