Jane is making a healthy snack of trail mix to sell as part of a fundraiser for the school hiking club. The mixture will have 2.5 times as many kilograms of raisins as of sunflower seeds. Sunflower seeds cost $12/kg and raisins cost $6/kg. If Jane has $108 dollars to spend, what mass of sunflower seeds and of raisins should she buy?
I have one formula, which is 12s + 6r = 108 but I need one more equation, plus how to solve it. Thank you!!!!