Tickets to the baseball game are on sale for $1.50 off the regular price. Dea buys 6 tickets. If her total cost is $51, how much is the regular price of each ticket
Let's assume the regular price of each ticket is 'x' dollars.
Since the tickets are on sale for $1.50 off the regular price, each ticket costs (x - $1.50) dollars.
Dea buys 6 tickets, so her total cost is 6 * (x - $1.50) = $51.
Therefore, 6x - 9 = $51.
Adding 9 to both sides, we get 6x = $60.
Dividing both sides by 6, we get x = $10.
Therefore, the regular price of each ticket is $10. Answer: \boxed{10}.