strate line thru 2 points: [(1/6) , -(1/3)] & [(5/6) , 1]
deltax=(5/6) - (1/6)=4/6 =2/3
deltay=1 - (-1/3)=4/3
slope=deltay / deltax =2
formula...y=2x +konst
projejt line from x=(5/6) tu x=0...this deltax=-5/6
deltay=-10/6
y at x=0...(5/6) -(10/6)=-5/6
point= (0,-5/6)
formula...y=2x-5/6