Question 41491
Here is such an example:

0.2345x + 6.25y=3.45
-0.2345x -4.72y = 7.63

This is easier to work by elimination because
the coefficients in the x-terms differ only 
in their signs.  So adding the equations eliminates
the x terms.  
Substiutution would require much more work.
Cheers,
Stan H.