Let
x = cost of a ticket for a senior
y = cost of a ticket for an adult
z = cost of a ticket for a student.
The first student buys 2 senior, 1 adult, and 2 student tickets for $51.
Therefore
2x + y + 2z = 51 (1)
Th second student buys 1 adult and 5 student tickets for $5.
Therefore
y + 5z = 55 (2)
The third student buys 2 senior, 2 adult, and 7 student tickets for $75.
Therefore
2x + 2y + 7z = 75 (3)
Answer:
The system of equation for determining x, y, and z is
2x + y + 2z = 51
y + 5z = 55
2x + 2y + 7z = 75
Warnng: The system of equations does not have a solution.