Answer:
![s+l=15](https://img.qammunity.org/2020/formulas/mathematics/middle-school/2oic2u5gzmkh8vz6h59s0u0vxbgmqsksrb.png)
![3s+6l=69](https://img.qammunity.org/2020/formulas/mathematics/middle-school/8tq5muushe6hkjepdzbtod7yzpp7dq353o.png)
's' represent number of small rooms and 'l' represent number of large rooms.
7 small rooms and 8 large rooms were reserved.
Explanation:
Let the variable 's' represent number of small rooms and 'l' represent number of large rooms.
Given:
Holding capacity of 1 small room = 3 people
Holding capacity of 1 large room = 6 people
Total number of rooms booked = 15
Total number of guests = 69
Using unitary method to get the number of people in 's' small and 'l' large rooms.
∵ 1 small room = 3 people
∴ 's' small rooms =
people
∵ 1 large room = 6 people
∴ 'l' large rooms =
people
Now, as per question,
Total rooms = 15
⇒
------------------- (1)
Total number of persons = 69
⇒
------------------- (2)
Therefore, the system of equations that could be used to determine the number of small rooms reserved and the number of large rooms reserved are:
![s+l=15](https://img.qammunity.org/2020/formulas/mathematics/middle-school/2oic2u5gzmkh8vz6h59s0u0vxbgmqsksrb.png)
![3s+6l=69](https://img.qammunity.org/2020/formulas/mathematics/middle-school/8tq5muushe6hkjepdzbtod7yzpp7dq353o.png)
Now, in order to find 's' and 'l', we rewrite equation (1) in terms of 's'. This gives,
![s=15-l](https://img.qammunity.org/2020/formulas/mathematics/middle-school/tjs0fbfqp5o7bqn3918ngqu4f8h9a86qzd.png)
Now, plug in the value of 's' in equation (2). This gives,
![3(15-l)+6l=69\\45-3l+6l=69\\3l=69-45\\3l=24\\l=(24)/(3)=8\\\therefore s= 15-l=15-8=7](https://img.qammunity.org/2020/formulas/mathematics/middle-school/7t7bgofwjqo95prs2swdd2cw6iaarqzuu0.png)
Therefore, 7 small rooms and 8 large rooms were reserved.