[tex]You can call c the number of children and a for adults; you get:5.20c+8.50a=1097.60anda=4c meaning that the number of adults was four times the children.Substituting this value of a into the first equation we get:5.2c+8.5(4c)=1097.65.2c+34c=1097.6rearranging:c=1097.639.2=28and so:a=4c=4⋅28=112[/tex]
I got: 28 children and 112 adults.