Question 940292
Get some graph paper.

Plot A and M, and draw a line from A through M 
and indefinitely beyond M.

{{{drawing(2400/7,400,-2,11,-10,4, grid(1),

circle(9,2,0.15),circle(9,2,0.13),circle(9,2,0.11),circle(9,2,0.09),circle(9,2,0.07),circle(9,2,0.05),circle(9,2,0.03),circle(9,2,0.01),
green(line(-7,-18,9,2)),locate(9.1,2,A), locate(5.1,-3,M),
circle(5,-3,0.15),circle(5,-3,0.13),circle(5,-3,0.11),circle(5,-3,0.09),circle(5,-3,0.07),circle(5,-3,0.05),circle(5,-3,0.03),circle(5,-3,0.01) )}}}

From A draw a vertical line segment (in red) down to the same level as M,
then from the endpoint of that line segment draw a horizontal line segment
left over to M.  Count the number of units you went down, which was 5 units
down. Now count the number of units you went left to get to M, which was
4 units left.

{{{drawing(2400/7,400,-2,11,-10,4, grid(1),

circle(9,2,0.15),circle(9,2,0.13),circle(9,2,0.11),circle(9,2,0.09),circle(9,2,0.07),circle(9,2,0.05),circle(9,2,0.03),circle(9,2,0.01),
green(line(-7,-18,9,2)),locate(9.1,2,A), locate(5.1,-3,M),

red(line(9,2,9,-3),line(9,-3,5,-3)),
circle(5,-3,0.15),circle(5,-3,0.13),circle(5,-3,0.11),circle(5,-3,0.09),circle(5,-3,0.07),circle(5,-3,0.05),circle(5,-3,0.03),circle(5,-3,0.01) )}}}  

Now do the same thing at M.  Draw a line 5 units down, then 4 units left,
and you'll end up at B.

{{{drawing(2400/7,400,-2,11,-10,4, grid(1),

circle(9,2,0.15),circle(9,2,0.13),circle(9,2,0.11),circle(9,2,0.09),circle(9,2,0.07),circle(9,2,0.05),circle(9,2,0.03),circle(9,2,0.01),
green(line(-7,-18,9,2)),locate(9.1,2,A), locate(5.1,-3,M),

red(line(9,2,9,-3),line(9,-3,5,-3),line(5,-3,5,-8),line(5,-8,1,-8)),
circle(5,-3,0.15),circle(5,-3,0.13),circle(5,-3,0.11),circle(5,-3,0.09),circle(5,-3,0.07),circle(5,-3,0.05),circle(5,-3,0.03),circle(5,-3,0.01) )}}}

So mark the point B where you ended up, at (1,-8).  Erase the rest of
the green line.

{{{drawing(2400/7,400,-2,11,-10,4, grid(1),

circle(9,2,0.15),circle(9,2,0.13),circle(9,2,0.11),circle(9,2,0.09),circle(9,2,0.07),circle(9,2,0.05),circle(9,2,0.03),circle(9,2,0.01),
green(line(1,-8,9,2)),locate(9.1,2,A), locate(5.1,-3,M),
locate(1.1,-8,B),

circle(1,-8,0.15),circle(1,-8,0.13),circle(1,-8,0.11),circle(1,-8,0.09),circle(1,-8,0.07),circle(1,-8,0.05),circle(1,-8,0.03),circle(1,-8,0.01),




red(line(9,2,9,-3),line(9,-3,5,-3),line(5,-3,5,-8),line(5,-8,1,-8)),
circle(5,-3,0.15),circle(5,-3,0.13),circle(5,-3,0.11),circle(5,-3,0.09),circle(5,-3,0.07),circle(5,-3,0.05),circle(5,-3,0.03),circle(5,-3,0.01) )}}}

Answer: (1,-8)

Edwin</pre>