a. Let the cost of an adult ticket be x and Let the cost of an children's ticket be y
We can deduce that;
![155x+230y=1285.5](https://img.qammunity.org/2023/formulas/mathematics/college/nbwltodtmnqr4z1dlw59fax05dchdvmhzz.png)
Also Mrs. Ramirez paid 53.75 for 2 adult tickets and 3 children tickets, so;
![2x+3y=53.75](https://img.qammunity.org/2023/formulas/mathematics/college/npcfk4ftxjf6jk7knfbcxooijnaa7hbswk.png)
We can solve this simultaneously for x and y.
So, we have;
![\begin{gathered} 155x+230y=1285.5----i \\ 2x+3y=53.75\text{ ----i}i \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/99cvsv88s3f7elh3axbbh4ah0a2z2h1wii.png)
Let's make x the subject of the relation, we have
![\begin{gathered} 2x=53.75-3y \\ x=(53.75-3y)/(2) \\ \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/xk4m1wkd3rj75827cal3u84403r9ylzq4i.png)
Let us substitute this relation for x in equation i
![undefined]()