Can someone find X and Y for me

At the newest animated movie, for every 9 children, there are 4 adults. there are a total of 39 children and adults at the movie.

Which simplifys to a+ b? a-(1-b)+1 -(1-a)-b+1 (a--1) -1)+1

One number is 4 less than 3 times a second number. if 3 more than two times the first number is decreased by 2 times the second number, the result is 11. use the substitution method. what is the first number?