Please help me quickly !!

Mr and mrs smith buy tickets for themselves and their four children. the cost of an adult ticket is ? 6 more than the adult ticket. the total cost of the six tickets is ? 40.50 work out the cost of an adult ticket. in your working let c be the cost of the child ticket and a be the cost of the adult ticket.

Atransformation t : (x, y) (x-5,y +3) the image of a(2,-1) is

What is the point of inflection for the function f(x)=2cos4x on the interval (0, pi/2)