Question 1042228
adult tickets sold=x
child tickets sold=83-x.  One could use x and y, but this way keeps it with one variable
7x+4(83-x)=527
7x+332-4x=527
3x+332=527
3x=195
x=65.  If it is not an integer, something is wrong in the problem or the solution.
65 adult tickets@$7=$455  ANSWER
18 child tickets$4=$72
Total is $527.