Answer:
substitution entry fee=$10 each ticket=$2
Explanation:
Gwen x+10y=30 and Tristan x+15y=40
subtract equations to get rid of x, you get 5y=10
5x2=10 so y=2
Cost of each ticket is $2
x+10(2)=30
10x2=20 30-20=10
So the entry fee is $10
I did all the questions and equations from part A to E and got them correct.