A firm is planning to spend $75,000 on advertising. It costs $3000 per minute to advertise on television and $1000 per minute to advertise on radio. If the firm buys X minutes of television advertising and Y minutes of radio advertising, its revenue in thousands of dollars is given by -0.3x^2-0.4y^2+0.8xy+5x+10y. How can the firm maximize its revenue? Formulate the written model and solver model. You also need to include a graph or table proving the solution is optimal.