Answer:
Children: 204
Adults: 85
Explanation:
Representation: let k represent the number of children and a the number of adults.
Equations: k + a = 289 (numbers of people)
($4/child)k + ($6/adult)a = $1,326
Let's solve this system of equations by substitution. Since k + a = 289, a = 289 - k. Substituting 289 - k for a above, we get this equation in one variable:
($4/child)k + ($6/adult)(289 - k), or, without units, 4k + 1734 - 6k = 1326.
The next step is to combine like terms: -2k = -408.
Dividing both sides by -2, we get k = 204. There are 204 children in the pool and 289 - 204 adults, or 85 adults.
Children: 204
Adults: 85