Tracy wants to buy some food for her slumber party. Great Foods Grocery Store is selling 2 bags of potato chips for $6.50 and 5 two-liter sodas for $3.00. Best Foods Grocery Store is selling 2 bags of potato chips for $5.00 and 3 two-liter sodas for $2.00. If p = potato chips and s = two-liter sodas, write a system of equations to model this problem\