A firm is planning to spend $10,000 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...

A firm is planning to spend $10,000 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 -2x²
-y²
+ xy + 8x + 3y. How can the firm maximize its revenue?