By elimination:

First eliminate  and find .
Multiply the first equation through by  
and the second equation through by :



Now add vertically term by term:



Divide both sides by 





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Next eliminate  and find .
Multiply the first equation through by 
 and the second equation through 
by :



Now add vertically term by term:



Divide both sides by 





Solution:   

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Now do the same problem from scratch using
substitution:



Solve the first equation for :



Add  to both sides:



Divide through every term by 3:



Simplify:



Substitute  for 
in the second equation:



Distribute:


Add  to both sides:


Divide both sides by 



Now substitute  for 
in



Write the  as  and 
write the  as 




The LCD is 
Multiply the  by 





Solution:  

Edwin