Please answer! Lots of points

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 are the equivalent ratios for 24/2= /3= /5.5=108/ = /15

Write the point-slope form of the line passing through (2, -12) and parallel to y=3x.