Question 169162
The Smith family pays $60 for 4 adult meals and 1 kid's meal.
The Jones family pays $42 for 2 adult meals and 2 kid's meals.
How much was each adult meal and each kid's meal. 
Here is what I have so far . . . 
4x + y = 60
+ 2x + 2y = 42
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6x + 3y = $102 
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4x + y = 60
2x + 2y = 42 Divide this one by 2
x + y = 21  Subtract this one from the 1st one, the Smiths
3x + 0y = 39
x = 13
The idea is to multiply one of the eqns so that one variable has the same coefficient.  Then you can add or subtract to eliminate that variable.  What you did is correct, but it didn't help.
Adult meal = $13
Kids' meal = $8