Question 1037999
John's mother is five times as old as John is. 
<pre>
M = 5J
</pre>
Three years ago,... 
<pre>
Three years ago, the mother was M-3
Three years ago, John was J-3
</pre>
Three years ago, she was 9 times his age. 
<pre>
M-3 = 9(J-3)

{{{system(M=5J,M-3=9(J-3))}}}

Solve by substituting 5J for M in the second equation,
solving for J, then substituting what you get to find M.

Edwin</pre>