Answer:
112 tickets for adults and 63 tickets for children
Step-by-step explanation:
In this case we can solve it using a 2x2 system of equations, like this:
let x: adult's tickets
let y: children's tickets
SW:
5 * x + 2 * y = 686
x + y = 175 => x = 175 - y
Replacing, we are left with that:
5 * (175 - y) + 2 * y = 686
875 - 5 * y + 2 * y = 686
- 5 * y + 2 * y = 686 - 875
-3 * y = -189
y = -189 / -3
y = 63
Now to calculate x:
x = 175 - 63
x = 112
It means that there were 112 tickets for adults and 63 tickets for children