Use matrices to solve applications of systems of linear equations

Question

Admission to a movie theater is $7 for children and $11 for adults. On a certain day, 57 people bought tickets at the theater and $499 was collected. How many children's tickets were sold and how many adult's tickets were sold?

Answer 1

X+Y = 57

7x + 11y = 499

x = 57-y

7(57-y) + 11y = 499

399 - 7y + 11y = 499

399 + 4y = 499

4y = 100

y = 25

x = 57-25 = 32

32 children

25 adult