Question 105806
You're not doing anything wrong. 
When you solve and get an answer like that. 
{{{18=12}}}
that means that there are no x,y that make these equations true. 
In other words, there is no solution. if
you look at the equations you can see why. 
1.{{{2x + 3y = 9}}}
2.{{{4x + 6y = 12}}}
If I multiply the first equation by 2, I get the left hand side of the second equation but not the right hand side. 
1.{{{4x+ 6y = 18}}}
2.{{{4x + 6y = 12}}}
These equations are inconsistent. 
Its like saying A=C and B=C, but A does not equal B. 
It doesn't make sense. 
You're correct in your derivation. No solution.