



 
Let me illustrate with a different pair of equations
and
I am going to solve the problem and then explain why I chose the steps I did. First multiply the first equation by 4 and the second equation by 3 to get
Look at the coefficients of y in the two equations, one is 12 and the other is 12. 8x  12y is 16 and 15x + 12y is 30 so (8x 12y) + (15x + 12y) is 16 + 30, that is
or
I hope now you can see why I wanted the coefficients of y in the two equations to be 12 and 12. When I added the two equations the yterm was "eliminated". To complete the problem substitute x = 2 into either of the two original equations and solve for y. Before you go back to your problem look at mine again
and
I chose to eliminate y but I could have eliminated x. To do so multiply the first equation by 5 and the second by 2 and add the resulting equations. Check that you got the same answer that you obtained by eliminating y. Now try your problem,  


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