Area of a triangle pls help me

Really need on these. i have no idea what to do

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.

In the figure shown below, m < 40 and ab =8. which equation could be used to find x?