Question 350623
First find the slope of the line containing the points ({{{1}}},{{{-3}}}) and ({{{2}}},{{{-3}}}).
{{{m=(y[2]-y[1])/(x[2]-x[1])=(-3-(-3))/(2-1)}}}
{{{m=0}}}
The line containing those two points is horizontal. 
The line perpendicular to a horizontal line is vertical and has the form,
{{{x=a}}}
so then,
{{{Ay=(2-A)y}}}
{{{A=2-A}}}
{{{2A=2}}}
{{{A=1}}}
Then,
{{{Ax+Ay-2=(2-A)y}}}
{{{x+y-2=y}}}
{{{highlight(x=2)}}}
.
.
.
{{{drawing(300,300,-6,6,-6,6,circle(1,-3,0.2),circle(2,-3,0.2),grid(1),blue(line(2,100,2,-100)),graph(300,300,-6,6,-6,6,-3))}}}