Answer:
There were 7 adults and 9 children paying tickets to the magic show
Explanation:
System of Equations
A system of equations consists of more than one variable related to more than one equation. The question we're working on requires to know two variables: the number of children and the number of adults that paid to a magic show.
Let's call x to the number of adults and y to the number of children. The first condition states there are a total of 16 persons in the group. This can be written as:
[1]
We also know the adult tickets cost $10.50 each and child tickets cost $7.50 each. This means the total amount paid for the tickets is:
![total\ paid = 10.50*x+7.50*y](https://img.qammunity.org/2021/formulas/mathematics/high-school/8vuked6sq8fng0eul5d3ppcmpxk41ayy80.png)
We are given this total, thus
[2]
The system formed by [1] and [2] must be solved to answer the question. Let's solve [1] for x:
![x=16-y](https://img.qammunity.org/2021/formulas/mathematics/high-school/lxbn7vu4ch5689fiwkjbeta4ryzenoh3je.png)
And substitute x in [2]:
![10.50*(16-y)+7.50*y=141](https://img.qammunity.org/2021/formulas/mathematics/high-school/yfq9yaarpxihuvrgq2cq1br0l20cgqmgkz.png)
Operating:
![10.50*16-10.50*y+7.50*y=141](https://img.qammunity.org/2021/formulas/mathematics/high-school/s0pkj5iu4coib2qspe3ssivv809snxx6xf.png)
![-10.50*y+7.50*y=141-10.50*16](https://img.qammunity.org/2021/formulas/mathematics/high-school/xt30esjq6jj60t5nz0o49zwhnwb7549gh4.png)
Joining like terms and operating on the right side:
![-3y=-27](https://img.qammunity.org/2021/formulas/mathematics/high-school/7tveme3pb68oujdhsfx7wtxb81f0k76fpd.png)
Solving:
![\displaystyle y=(-27)/(-3)](https://img.qammunity.org/2021/formulas/mathematics/high-school/a90oo9gstaobtdrsv4yquvsnhicqszqhqk.png)
![\boxed{y=9}](https://img.qammunity.org/2021/formulas/mathematics/high-school/hos2m0kv7ewtqftaxerxfs5znfayrn3lg6.png)
The value of x is calculated by
x=16-y=16-9
![\boxed{x=7}](https://img.qammunity.org/2021/formulas/mathematics/college/92hojso9r4phwk2svthlufl2b7ozmb668c.png)
This means there were 7 adults and 9 children paying tickets to the magic show