Let's use the variable x to represent the cost of one adult meal, and y to represent the cost of one child meal.
If the cost of 82 adult meals and 96 children meals is $5,664, we can write the following equation:
[tex]82x+96y=5664[/tex]If the cost of 65 adult meals and 49 children meals is $4,002, we can write the equation:
[tex]65x+49y=4002[/tex]To solve this system, let's solve the second equation for y and then use its value in the first equation:
[tex]\begin{gathered} 65x+49y=4002 \\ 49y=4002-65x \\ y=\frac{4002-65x}{49} \\ \\ 82x+96y=5664 \\ 82x+96(\frac{4002-65x}{49})=5664 \\ 82x+7840.653-127.347x=5664 \\ -45.347x=-2176.653 \\ x=48 \\ \\ y=\frac{4002-65\cdot48}{49} \\ y=18 \end{gathered}[/tex]Therefore every adult meal costs $48 and every child's meal costs $18.