May I please get help with my math lesson if possible I don't know why they are 4 answers if 1 of the answers don't apply to any of the questions it fine just leave it blank

Answer: S1:E7 ; S2:E1 ; S3:E5
Step-by-step explanation:
What we know:
**A lot of info is problem-specific.
How to solve:
Since we only need to write the equations, we simply need to find the x and y variables, and the total.
Process:
Problem 1:
Problem 2:
Problem 3:
Solution: S1:E7 ; S2:E1 ; S3:E5