Let \( p \) represent the regular price of each ticket. Since the tickets are on sale for $1.50 off the regular price, the sale price of each ticket is \( p - 1.50 \).
Dea buys 6 tickets at the sale price, so her total cost is given by:
\[ 6(p - 1.50) = 51 \]
Now, we can solve this equation step by step:
- Distribute the 6:
\[ 6p - 9 = 51 \]
- Add 9 to both sides:
\[ 6p = 60 \]
- Divide by 6:
\[ p = 10 \]
Thus, the regular price of each ticket is $10.
In summary, the regular price of each ticket is $10, which is determined from the equation representing the total cost of 6 tickets after applying the discount.