What is three times nine

Acarnival sold tickets for $1.50 for adults and $1.00 for students. there were 54 tickets sold for a total of $70.50. write a system of equations to represent the number of adult tickets, x, and the number of student tickets, y. find the solution and explain what it means. i'll you if you me

Given the equation f(x)=a(b)x where the initial value is 40 and the growth rate is 20% what is f(4)

I'm confused on this could anyone me and show me what i need to do to solve it.