Find the length of the leg x

For each proportion find the unknown number x 1/5/8=×/15

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?

What is the slope of the line (-7,2) (4,6)