I need help with these 2

Solve the system of equations. y= 2x y= x^2 - 15

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

Which of the choices shown could be used to prove that aacp=abcp ?