By trial and error, I got it first correctly. The granola
bars cost $1 each and the yogurt is $.50 per cup. By plugging this in to each
equation, you'll see that 12 granola bars equals $12, and 7 cups of yogurt
equals $3.50, for a total of $15.50. The second account would produce $6 +
$5.50, which equals $11.50.
