Set up a system of equations describing the following word problem. Be sure to specify what each variable represents.
Blue beads cost $0.50 per ounce and green beads cost $0.75 per ounce. Janine wants to mix blue and green beads to get 10 ounces of a bead mixture worth $0.55 per ounce. Wow...Janine has some extremely specific designs on these beads, it seems. Hey, good for her for knowing exactly what she wants.
How many ounces of each color does Janine need to buy?