What is the value of f(x) = 3x - 12 for x = 9

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.

Asailor is looking at a kite. if he is looking at the kite at an angle of elevation of 36and the distance from the boat to the point where the kite is directly overhead is 40 feet, how high is the kite?

Need this at the city museum, child admission is 6 and adult admission is 9.20. on tuesday, 132 tickets were sold for a total sales of 961.60. how many adult tickets were sold that day?