Answer:
![30-8p](https://img.qammunity.org/2020/formulas/mathematics/high-school/tpaxi4hizy5bbmeiepvdzgvfpdb5rgjpkc.png)
Explanation:
Let p represent cost of each drink.
We have been given that the medium pizza costs two times as much as one drink, so the cost of medium pizza would be
.
We are also told that the large pizza costs three times as much as one drink, so the cost of la pizza would be
.
We have been given that Mary wants to buy one large pizza, one medium pizza, and three drinks.
Since the cost of one drink is p, so cost of 3 three drinks would be
.
The total cost of one large pizza, one medium pizza, and three drinks would be
![2p+3p+3p=8p](https://img.qammunity.org/2020/formulas/mathematics/high-school/cqpk9o9ux495ei6vl1841fx45fxdi9lgqs.png)
Mary started with $30, so amount left after all of her purchases would be 30 minus total cost of all purchases.
![30-8p](https://img.qammunity.org/2020/formulas/mathematics/high-school/tpaxi4hizy5bbmeiepvdzgvfpdb5rgjpkc.png)
Therefore, Mary will have
dollars left after making all of her purchases.