Let \( x \) be the regular price of a ticket. Since the tickets are on sale for $1.50 off the regular price, the sale price of a ticket is \( x - 1.50 \).
Dea buys 6 tickets, so the total cost she pays can be expressed as:
\[ 6(x - 1.50) \]
According to the problem, this total cost is $51. Therefore, we can set up the equation:
\[ 6(x - 1.50) = 51 \]
Now, let's solve for \( x \).
- Distribute the 6:
\[ 6x - 9 = 51 \]
- Add 9 to both sides:
\[ 6x = 60 \]
- Divide both sides by 6:
\[ x = 10 \]
Thus, the regular price of a ticket is $10.00.