For this case we have to:
x: It is the variable that represents the quantity of paint bottles
y: It is the variable that represents the number of boxes of colored pencils
So, we have:

If you can not spend more than $ 42 then we have:

Then you can buy 10 boxes of colored pencils and 3 of paint bottles at a cost of $ 41

You can buy 5 boxes of colored pencils and 12 of paint bottles at a cost of $

You can buy 7 boxes of colored pencils and 8 of paint bottles at a cost of $

Answer:
