Tickets to the zoo cost $14 for adults and $10 for children. A group of 12 people went to the zoo, and the tickets cost $140. The system of equations models this situation, where x is the number of adults and y is the number of children.
x+y=12
14x+10y=140
How many adults and how many children were in the group?
x is the number of adults and y is the number of children. x + y = 12 14x + 10y = 140 lets multiply the first equation by -10 and then add it to the second equation: -10x - 10y = -120 14x + 10y = 140 ----------------------- 4x + 0 = 20 x = 20/4 x = 5 then substitute in the original equation: x + y = 12 5 + y = 12 y = 12 - 5 y = 7 therefore there were 5 adults and 7 children
