Find the surface area of the triangular prism. and equation plz

What is the value of x? enter your answer in the box. (cm)

Galen sold tickets of his church’s carnival for a total of $2,820. children’s tickets cost $3 each and adult tickets cost $5 each. the number of children’s tickets sold was 30 more than 3 times the number of adult tickets slod. how many children’s ticket and how many adult tickets did he sell?

Pls never taught i’m really confused and i rlly need