Molly is an insurance agent. She is mailing packages filled with marketing items to a few of her clients. The items she is including are pens that weigh x ounces, notepads that weigh y ounces, and magnets that weigh z ounces: A package filled with 3 pens, 2 notepads, and 1 magnet weighs 8 ounces. A package filled with 2 pens, 1 notepad, and 2 magnets weighs 3.9 ounces. A package filled with 4 pens and 3 magnets weighs 4 ounces. Which matrix equation can be solved to find the weight of each item?