The domain is

and the range is

Domain is x values (horizontal axis), while range is y values (vertical axis). On a line like this one, domain is calculated from the left most point to the right most, while range is calculated from the down most to the upmost.
Because this line is a solid line rather than a dotted line, less than or equal to

signs are used rather than just

less than signs.
Answer:
2.5 hours
Step-by-step explanation:
The product of speed and time is distance. If the distance is the same, then time is inversely proportional to speed. At 60/50 = 6/5 times the speed, the return trip will take 5/6 times the time:
(5/6)(3 hours) = 2.5 hours . . . time for return trip
Step-by-step explanation:
using the quadratic formula......
Hector = 2s or h/2
Sister = s
Equation: h/2 = s
Substitution: (20)/2 = s
10 = s
Hector’s sister found 10 seashells.