A homeowner is making plans to landscape her yard. She plans to hire professionals to install grass sod in some parts of the yard and flower beds in other parts. Grass sod installation costs $2 per square foot and flower bed installation costs $12 per square foot. Her budget for the project is $3,000. Write an equation that represents the square feet of grass sod, x, and the square feet of flower beds, y, that she could afford if she used her entire budget.