I’m so confused on shapes of pls help me

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.

What is the y intercept of f(x)=(1/2)^x?

Can someone pls ! pls answer all. no explanation needed..