If the output number is 27, what was the input number ?

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.

Can someone check if i did this right since i really want to make sure it’s correct. if you do you so much

Find the solution(s) to x^2-14+49=0