Setting up a system of equations for a matrix

The director of a public playground is ordering a supply of baseball equipment. He wishes to have two gloves for every ball and one bat for every three gloves. The unit prices for gloves, bats, and balls are $4.00, $3.00, and $0.50, respectively. The director has a budget of $157.50.

What equipment should be ordered?

Set up the system of equations (don’t forget to define your variables), put it in matrix format, and solve using row operations to get to the reduced row-echelon form.

I'm just not sure how to set up the system of equations, i don't need help with the actual matrix part

thanks for any help