Name the property the equation illustrates

Which expression calculates the speed in meters per second of an object that travels a distance of 100 m every 20 seconds

Through: (-3,-3) parallel to y= 7/3x+3

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?