Question 470674
{{{m=(y2-y1)/(x2-x1)=(2-2)/(0-2)=0}}}
y-y1=m(x-x1) plug in your m and one of the points, doesn't matter which
y-2=0(x-0)
y-2=0
y=2 
i think you copied wrong
it's ax+by=c 
so a=0
b=1
c=2